Science Cyber

Configure PPP-PAP

2012-01-15T16:29:00.000+07:00

Below to config PPP-PAP

#username R1 password cisco
#int se0/0/0
#encap ppp
#ppp authen pap

Access Control List ( ACL )

2012-01-15T03:25:00.000+07:00

ACL Standard
#ip access-list standar NO_Access
#deny host 192.168.10.1
#permit 192.168.11.0 0.0.0.255 ==IP network
#int se0/0/0 ===ip router
#ip access-group NO_Access out

ACL Extended

#ip access-list extended NO_Access
#deny (name_port) host 192.168.1.1 any eq 80
#permit (name_port) 192.168.1.0 0.0.0.255 any ===all network (If one host, you can create : #permit (name_port) 192.168.1.1 host 192.168.2.1 0.0.0.0)
#int fa0/1
#ip access_group NO_Access

Create VTP mode

2012-01-15T03:15:00.000+07:00

Vtp server :

#vtp mode server
#vtp domain unisbank
#vtp password cisco

Vtp client :

#vtp mode client
#vtp domain unisbank
#vtp password cisco

show vtp status

Configuration Membership, Trunk Vlan and Inter Vlan

2012-01-15T03:12:00.000+07:00

Membership (ke client)
#vlan 10
#name komputer
#int range fa0/1-fa0/24
#switch mode access
#switch access vlan 10

Trunking Vlan (antar switch dan router)
#vlan 99
#name trunk
#exit
#int fa0/24
#switchport mode trunk

#switchpor trunk native vlan 99

Inter Vlan (settting at the router)
#int fa0/1.10
#encapsulation dot1q 10
#ip add 192.168.10.254 255.255.255.0

Show vlan

CPU history

2012-01-14T06:21:00.002+07:00

The central processing unit (CPU) is the portion of a computer system that carries out the instructions of a computer program, to perform the basic arithmetical, logical, and input/output operations of the system. The CPU plays a role somewhat analogous to the brain in the computer. On large machines, CPUs require one or more printed circuit boards. On personal computers and small workstations, the CPU is housed in a single silicon chip called a microprocessor. Modern CPUs are large scale integrated circuits in packages typically less than four centimeters square, with hundreds of connecting pins.
An array processor or vector processor has multiple parallel computing elements, with no one unit considered the "center". Since the term "CPU" is generally defined as a device for software (computer program) execution, the earliest devices that could rightly be called CPUs came with the advent of the stored-program computer.
It was the outline of a stored-program computer that would eventually be completed in August 1949.^[2]Significantly, the programs written for EDVAC were stored in high-speed computer memory rather than specified by the physical wiring of the computer. With von Neumann's design, the program, or software, that EDVAC ran could be changed simply by changing the contents of the memory.
Early CPUs were custom-designed as a part of a larger, sometimes one-of-a-kind, computer. The IC has allowed increasingly complex CPUs to be designed and manufactured to tolerances on the order of nanometers. Both the miniaturization and standardization of CPUs have increased the presence of digital devices in modern life far beyond the limited application of dedicated computing machines. While von Neumann is most often credited with the design of the stored-program computer because of his design of EDVAC, others before him, such as Konrad Zuse, had suggested and implemented similar ideas. The so-called Harvard architecture of the Harvard Mark I, which was completed before EDVAC, also utilized a stored-program design using punched paper tape rather than electronic memory. Most modern CPUs are primarily von Neumann in design, but elements of the Harvard architecture are commonly seen as well.
Relays and vacuum tubes (thermionic valves) were commonly used as switching elements; a useful computer requires thousands or tens of thousands of switching devices. The overall speed of a system is dependent on the speed of the switches. Tube computers like EDVAC tended to average eight hours between failures, whereas relay computers like the (slower, but earlier) Harvard Mark I failed very rarely.^[1]The control unit of the CPU contains circuitry that uses electrical signals to direct the entire computer system to carry out stored program instructions. The control unit must communicate with both the arithmetic/logic unit and memory. The design complexity of CPUs increased as various technologies facilitated building smaller and more reliable electronic devices. CPUs based upon these "building block" ICs are generally referred to as "small-scale integration" (SSI) devices. SSI ICs, such as the ones used in the Apollo guidance computer, usually contained up to a few score transistors. To build an entire CPU out of SSI ICs required thousands of individual chips, but still consumed much less space and power than earlier discrete transistor designs. As microelectronic technology advanced, an increasing number of transistors were placed on ICs, thus decreasing the quantity of individual ICs needed for a complete CPU. MSI and LSI (medium- and large-scale integration) ICs increased transistor counts to hundreds, and then thousands.
In 1964 IBM introduced its System/360 computer architecture which was used in a series of computers that could run the same programs with different speed and performance. In stark contrast with its SSI and MSI predecessors, the first LSI implementation of the PDP-11 contained a CPU composed of only four LSI integrated circuits.^[4]
Transistor-based computers had several distinct advantages over their predecessors. Aside from facilitating increased reliability and lower power consumption, transistors also allowed CPUs to operate at much higher speeds because of the short switching time of a transistor in comparison to a tube or relay. Additionally while discrete transistor and IC CPUs were in heavy usage, new high-performance designs like SIMD (Single Instruction Multiple Data) vector processors began to appear.

Blogger History

2012-01-14T06:19:00.003+07:00

Blogger is a blog-publishing service that allows private or multi-user blogs with time-stamped entries. Generally, the blogs are hosted by Google at a subdomain of blogspot.com. Up until May 1, 2010 Blogger allowed users to publish blogs on other hosts, via FTP. On August 23, 1999, Blogger was launched by Pyra Labs. In February 2003, Pyra Labs was acquired by Google under undisclosed terms. In October 2004, Pyra Labs' co-founder, Evan Williams, left Google. In 2004, Google purchased Picasa; it integrated Picasa and its photo sharing utility Hello into Blogger, allowing users to post photos to their blogs.
On May 9, 2004, Blogger introduced a major redesign, adding features such as web standards-compliant templates, individual archive pages for posts, comments, and posting by email. On August 14, 2006, Blogger launched its latest version in beta, codenamed "Invader", alongside the gold release. By May 2007, Blogger had completely moved over to Google operated servers.

As part of the Blogger redesign in 2006, all blogs associated with a user's Google Account were migrated to Google servers. New features are discussed in the service's official blog.

In September 2009, Google introduced new features into Blogger as part of its tenth anniversary celebration. The features included a new interface for post editing, improved image handling, Raw HTML Conversion, and other Google Docs-based implementations, including:

Vertical re-sizing of the post editor. Link editing in Compose mode.

New toolbar with Google aesthetics, faster loading time, and "undo" and "redo" buttons. In 2010, Blogger introduced new templates and redesigned its website. The Google Toolbar has a feature called "BlogThis!" which allows toolbar users with Blogger accounts to post links directly to their blogs.

"Blogger for Word" is an add-in for Microsoft Word which allows users to save a Microsoft Word Document directly to a Blogger blog, as well as edit their posts both on- and offline. As of January 2007, Google says "Blogger for Word is not currently compatible with the new version of Blogger", and they state no decision has been made about supporting it with the new Blogger.^[9]Blogger supports Google's AdSense service as a way of generating revenue from running a blog.

Blogger offers multiple author support, making it possible to establish group blogs.

Blogger offers a template editing feature, which allows users to customize the Blogger template.

Google Docs has direct publishing integration to Blogger.

Windows Live Writer, a standalone app of the Windows Live suite, publishes directly to Blogger.

Kazakhstan

Syrian Arab Republic

Zip Code

2012-01-14T06:17:00.001+07:00

ZIP codes are a system of postal codes used by the United States Postal Service (USPS) since 1963. An extended ZIP+4 code, introduced in the 1980s, includes the five digits of the ZIP code, a hyphen, and four more digits that determine a more precise location than the ZIP code alone.

Simultaneously with the introduction of the ZIP code, two-letter state abbreviations were introduced. ^[3] The post office gives credit to Moon for only the first three digits of the ZIP code, which describe the sectional center facility (SCF) or "sec center." An SCF is a central mail processing facility with those three digits. The SCF sorts mail to all post offices with those first three digits in their ZIP codes. The mail is sorted according to the final two digits of the ZIP code and sent to the corresponding post offices in the early morning. The United States Post Office used a cartoon character, whom it called Mr. ZIP, to promote use of the ZIP code.

In 1983, the U.S. Postal Service began using an expanded ZIP code system that it called ZIP+4, often called "plus-four codes", "add-on codes", or "add ons".
A ZIP+4 code uses the basic five-digit code plus four additional digits to identify a geographic segment within the five-digit delivery area, such as a city block, a group of apartments, an individual high-volume receiver of mail or any other unit that could use an extra identifier to aid in efficient mail sorting and delivery. For post-office boxes, the general (but not invariable) rule is that each box has its own ZIP+4 code. It is common to use add-on code 9998 for mail addressed to the postmaster (to which requests for pictorial cancellations are usually addressed), 9999 for general delivery and other high-numbered add-on codes for business reply mail.^{[citation needed]} For a unique ZIP code (explained below), the add-on code is typically 0001.
For example ZIP code 42223 spans Christian KY and Montgomery TN, and ZIP code 97635 spans Lake OR and Modoc CA.
A sectional center facility may have more than one three-digit code assigned to it. For example, the Northern Virginia sectional center facility in Merrifield is assigned codes 220, 221, 222 and 223. The lowest ZIP code is in Holtsville, New York (00501, a ZIP code exclusively for the U.S. Internal Revenue Service center there). Other low ZIP codes are 00601 for Adjuntas, Puerto Rico; 01001 for Agawam, Massachusetts, and 01002 for Amherst, Massachusetts.

Despite the geographic derivation of most ZIP codes, the codes themselves do not represent geographic regions; in general, they correspond to address groups or delivery routes. For example, some residents in or near Haubstadt, Indiana, which has the zip code 47639, have mailing addresses with 47648, the ZIP code for neighboring Fort Branch, Indiana, while others living in or near Fort Branch have addresses with 47639. While the White House itself is located in ZIP code 20006, it has the ZIP code 20500. The Nuclear Regulatory Commission is located in Rockville, Maryland, at ZIP code 20852, but has been assigned by the Postal Service the address "Washington, DC 20555".

In rare circumstances, a locality is assigned a ZIP code that does not match the rest of the state; in other words, a ZIP code may cross state lines. Fishers Island, New York, bears the ZIP code 06390 and is served from Connecticut — all other New York ZIP codes (excepting those at Holtsville for the IRS) begin with "1".

Some Texas ZIP codes are served from New Mexico (most notably some El Paso ZIP codes) and thus bear codes beginning with "885" (contiguous numerically with 870-884 NM) rather than "799".

Fort Campbell (ZIP code 42223), primarily in Kentucky, main entrance is in Tennessee.

In essence the mail for the Kenton County Airport Board has an Ohio ZIP code but the physical address of the airport is a Kentucky ZIP code.

History of Book

2012-01-14T06:05:00.003+07:00

A single sheet within a book is called a leaf, and each side of a leaf is called a page. A book produced in electronic format is known as an electronic book (e-book).
The body of all written works including books is literature. In novels and sometimes other types of books (for example, biographies), a book may be divided into several large sections, also called books (Book 1, Book 2, Book 3, and so on). Books can also be borrowed from libraries. ^[4] Similarly, the Latin word codex, meaning a book in the modern sense (bound and with separate leaves), originally meant "block of wood".
^[5] Papyrus sheets were glued together to form a scroll. The Greek word for papyrus as writing material (biblion) and book (biblos) come from the Phoenician port town Byblos, through which papyrus was exported to Greece.^[7]Whether made from papyrus, parchment, or paper, scrolls were the dominant form of book in the Hellenistic, Roman, Chinese, and Hebrew cultures. The more modern codex book format form took over the Roman world by late antiquity, but the scroll format persisted much longer in Asia.
In the 5th century, Isidore of Seville explained the relation between codex, book and scroll in his Etymologiae (VI.13): "A codex is composed of many books; a book is of one scroll. The tradition and style of the Roman Empire still dominated, but slowly the peculiar medieval book culture emerged.
Before the invention and adoption of the printing press, almost all books were copied by hand, which made books expensive and comparatively rare.

Calligraphers, who dealt in fine book production

Finally, the book was bound by the bookbinder.

Irish monks introduced spacing between words in the 7th century. The first books used parchment or vellum (calf skin) for the pages. The book covers were made of wood and covered with leather. At first, books were copied mostly in monasteries, one at a time. With the rise of universities in the 13th century, the Manuscript culture of the time led to an increase in the demand for books, and a new system for copying books appeared. The books were divided into unbound leaves (pecia), which were lent out to different copyists, so the speed of book production was considerably increased. A number of cities in the medieval Islamic world had book production centers and book markets. The medieval Islamic world also used a method of reproducing reliable copies of a book in large quantities, known as check reading, in contrast to the traditional method of a single scribe producing only a single copy of a single manuscript. Modern paper books are printed on papers which are designed specifically for the publication of printed books. Typically, books papers are light weight papers 60 to 90 g/m² and often specified by their caliper/substance ratios (volume basis). This volume basis then allows the calculation of a books PPI (printed pages per inch) which is an important factor for the design of book jackets and the binding of the finished book. Different paper qualities are used as book paper depending on type of book: Machine finished coated papers, woodfree uncoated papers, coated fine papers and special fine papers are common paper grades.

Mapping

2012-01-14T06:02:00.001+07:00

Although most commonly used to depict geography, maps may represent any space, real or imagined, without regard to context or scale; e.g. brain mapping, DNA mapping, and extraterrestrial mapping.
Road maps are perhaps the most widely used maps today, and form a subset of navigational maps, which also include aeronautical and nautical charts, railroad network maps, and hiking and bicycling maps.

The orientation of a map is the relationship between the directions on the map and the corresponding compass directions in reality. In the Middle Ages many maps, including the T and O maps, were drawn with East at the top (meaning that the direction "up" on the map corresponds to East on the compass). Several kinds of maps are often traditionally not oriented with North at the top:

Maps from non-Western traditions are oriented a variety of ways. Old maps of Edo show the Japanese imperial palace as the "top", but also at the centre, of the map. Route and channel maps have traditionally been oriented to the road or waterway they describe.

Typical maps of the Arctic have 0° meridian towards the bottom of the page; maps of the Antarctic have the 0° meridian towards the top of the page.

Reversed maps, also known as Upside-Down maps or South-Up maps, reverse the "North is up" convention and have South at the top.

Buckminster Fuller's Dymaxion maps are based on a projection of the Earth's sphere onto an icosahedron. Modern digital GIS maps such as ArcMap typically project north at the top of the map, but use math degrees (0 is east, degrees increase counter-clockwise), rather than compass degrees (0 is north, degrees increase clockwise) for orientation of transects.

Large scale maps, say 1:10,000, cover relatively small regions in great detail and small scale maps, say 1:10,000,000, cover large regions such as nations, continents and the whole globe. Examples of large scale maps are the 1:25,000 maps produced for hikers; on the other hand maps intended for motorists at 1:250,000 or 1:1,000,000 are small scale.
The same applies to computer maps where the smallest unit is the pixel. Some maps, called cartograms, have the scale deliberately distorted to reflect information other than land area or distance. Near the center of the map stations are spaced out more than near the edges of map.

Maps of the world or large areas are often either 'political' or 'physical'. Topographic maps show elevations and relief with contour lines or shading. Perhaps the best-known world-map projection is the Mercator projection, originally designed as a form of nautical chart.

The functionality of maps has been greatly advanced by technology simplifying the superimposition of spatially located variables onto existing geographical maps.

replacing the map by a more detailed one

Printer Device

2012-01-14T05:59:00.003+07:00

Printers that include non-printing features are sometimes called multifunction printers (MFP), multi-function devices (MFD), or all-in-one (AIO) printers. Local printers are also increasingly taking over the process of photofinishing as digital photo printers become commonplace. Printers are routinely classified by the printer technology they employ; numerous such technologies have been developed over the years. Solid ink printers, also known as phase-change printers, are a type of thermal transfer printer. Solid ink printers are most commonly used as colour office printers, and are excellent at printing on transparencies and other non-porous media. Solid ink printers can produce excellent results. Acquisition and operating costs are similar to laser printers. Previously, solid ink printers were manufactured by Tektronix, but Tek sold the printing business to Xerox in 2001 A dye-sublimation printer (or dye-sub printer) is a printer which employs a printing process that uses heat to transfer dye to a medium such as a plastic card, paper or canvas. While once the province of high-end print shops, dye-sublimation printers are now increasingly used as dedicated consumer photo printers. The impact printer uses a print head that hits the surface of the ink ribbon, which presses the ink onto the paper. All but the dot matrix printer rely on the use of formed characters, letterforms that represent each of the characters that the printer was capable of printing. Impact printers varieties include, typewriter-derived printers, teletypewriter-derived printers, daisy wheel printers, dot matrix printers and line printers.

Ballistic wire printers (discussed in the dot matrix printers article)

Stored energy printers

24-pin print heads were able to print at a higher quality. Once the price of inkjet printers dropped to the point where they were competitive with dot matrix printers, dot matrix printers began to fall out of favor for general use.

Some dot matrix printers, such as the NEC P6300, can be upgraded to print in colour. Colour graphics are generally printed in four passes at standard resolution, thus slowing down printing considerably. Dot-matrix printers are now (as of 2005) rapidly being superseded even as receipt printers.

Line printers, as the name implies, print an entire line of text at a time. In drum printers, a drum carries the entire character set of the printer repeated in each column that is to be printed. In chain printers, also known as train printers, the character set is arranged multiple times around a chain that travels horizontally past the print line. Comb printers, also called line matrix printers, represent the third major design. These printers were a hybrid of dot matrix printing and line printing. Because far less motion was involved than in a conventional dot matrix printer, these printers were very fast compared to dot matrix printers and were competitive in speed with formed-character line printers while also being able to print dot matrix graphics.
Line printers were the fastest of all impact printers and were used for bulk printing in large computer centres.

uninterruptible power supply

2012-01-14T05:56:00.003+07:00

An uninterruptible power supply, also uninterruptible power source, UPS or battery/flywheel backup, is an electrical apparatus that provides emergency power to a load when the input power source, typically mains power, fails. A UPS differs from an auxiliary or emergency power system or standby generator in that it will provide instantaneous or near-instantaneous protection from input power interruptions by means of one or more attached batteries and associated electronic circuitry for low power users, and or by means of diesel generators and flywheels for high power users.

Common power problems

The primary role of any UPS is to provide short-term power when the input power source fails. However, most UPS units are also capable in varying degrees of correcting common utility power problems:

Power failure: defined as a total loss of input voltage.

The general categories of modern UPS systems are on-line, line-interactive or standby.^[3]In a standby ("off-line") system the load is powered directly by the input power and the backup power circuitry is only invoked when the utility power fails. For large power units, dynamic uninterruptible power supplies are sometimes used. When the mains power fails, an Eddy-current regulation maintains the power on the load as long as the flywheel's energy is exhausted. A hybrid (double conversion on demand) UPS operates as an off-line/standby UPS when power conditions are within a certain preset window. This allows the UPS to achieve very high efficiency ratings.

A motor driving a mechanically connected generator,

A hybrid rotary UPS, designed similar to an online UPS, except that it uses the flywheel in place of batteries. The rectifier drives a motor to spin the flywheel, while a generator uses the flywheel to power the inverter.

CLI Commands

2012-01-14T05:53:00.001+07:00

A command-line interface (CLI) is a mechanism for interacting with a computer operating system or software by typing commands to perform specific tasks. A command-line interpreter then receives, parses, and executes the requested user command. Upon completion, the command usually returns output to the user in the form of text lines on the CLI. A program that implements such a text interface is often called a command-line interpreter, command processor or shell, whereby the term shell, often used to describe a command-line interpreter, can be in principle any program that constitutes the user-interface, including fully graphically oriented ones—for example, the default Windows GUI is created by a shell program named EXPLORER.EXE, as defined in the SHELL=EXPLORER.EXE line in the WIN.INI configuration file.

Screenshot of the MATLAB 7.4 command-line interface and GUI.

In the case of operating systems (OS), MS-DOS and Unix each define their own set of rules that all commands must follow. A simple CLI will display a prompt, accept a "command line" typed by the user terminated by the Enter key, then execute the specified command and provide textual display of results or error messages. Advanced CLIs will validate, interpret and parameter-expand the command line before executing the specified command, and optionally capture or redirect its output.
Useful command lines can be saved by assigning a character string or alias to represent the full command, or several commands can be grouped to perform a more complex sequence — for instance, compile the program, install it, and run it — creating a single entity, called a command procedure or script which itself can be treated as a command. In some CLIs, the commands issued are not coupled to any conceptual place within a command hierarchy. A user can specify relative or absolute paths to any command or data. Examples of this include DOS, OS/2, Windows, and UNIX, which provide forms of a change directory command which allows access to any directory in the system. For example, if the CLI had two modes called interface and system, the user would enter the word 'interface' at the command prompt and then enter an interface mode, where a certain subset of commands and data are available. At this point system commands are not accessible and would not be accessible until the user explicitly exits the interface mode and enters the system mode.

Command prompt

A command prompt (or just prompt) is a sequence of (one or more) characters used in a command-line interface to indicate readiness to accept commands. In DOS's COMMAND.COM and in the Windows NT's command-line interpreter cmd.exe the prompt is modifiable by issuing a prompt command or by directly changing the value of the corresponding %PROMPT% environment variable.

[time] user@host: work_dir $

could be set by issuing the command
In RISC OS, the command prompt is a '*' symbol, and thus (OS)CLI commands are often referred to as "star commands".^[1]

Arguments

A command-line argument or parameter is an argument sent to a program being called. When a command processor is active a program is typically invoked by typing its name followed by command-line arguments (if any). For example, in Unix and Unix-like environments, an example of a command-line argument is:

Command-line option

A command-line option or simply option (also known as a flag or switch) modifies the operation of a command; the effect is determined by the command's program. Options follow the command name on the command line, separated by spaces. By appending the /owner option (to form the command directory/owner), the user can instruct the directory command to also display the ownership of the files.
Some command-line interpreters (including newer versions of DR-DOS COMMAND.COM and 4DOS) also provide pseudo-environment variables named %/% or %SWITCHAR% to allow portable batchjobs to be written.

Long path/Long program name Parameter one Parameter two ...

Long_path/Long_program_name Parameter_one Parameter_two ...,

"Long path/Long program name" "Parameter one" "Parameter two" ...

Command-line interpreter

A command-line interpreter (also called a command line shell, command language interpreter, or abbreviated as CLI) is a computer program that reads lines of text entered by a user and interprets them in the context of a given operating system or programming language.
Command-line interpreters allow users to issue various commands in a very efficient (and often terse) way. ^[2] For business application programs, text-based menus were used, but for more general interaction the command line was the interface.
From the early 1970s the Unix operating system on minicomputers pioneered the concept of a powerful command-line environment, which Unix called the "shell", with the ability to "pipe" the output of one command in as input to another, and to save and re-run strings of commands as "shell scripts" which acted like custom commands.
While most computer users now use a GUI almost exclusively, more advanced users have access to powerful command-line environments:

Scripting

Most command-line interpreters support scripting, to various extents. For a few operating systems, most notably DOS, such a command interpreter provides a more flexible command line interface than the one supplied. In other cases, such a command interpreter can present a highly customised user interface employing the user interface and input/output facilities of the language.

Recovering Lost Data: Data Recovery Software

2012-01-14T05:49:00.003+07:00

Recovering Lost Data: Data Recovery Software

While the iPhone is a complicated device, loss of data is no new thing. However, without panicking, you can recover your lost data by using a popular data recovery software specially designed for Apple devices. Follow the steps given below:

1. Before downloading any data recovery software, make sure you stop uploading new music or image files into your iPhone. 2. Download a good data recovery software for your iPhone that is capable of searching for the deleted files onto your phone's hard-drive. Tip: After a thorough crawling, the data recovery software will recover all your data back to its original place. Some more data recovery software are lined up below:

iPhone Backup Extractor

MiniTool Power Data Recovery

Data Recovery Mac

Take the following method into consideration if you've created a backup of your iPhone's data into your PC/Mac with the help of iTunes.

Recovering Lost Data: iTunes

Just a single sync, and you have all your data backed up in iTunes.

1. The first step is to connect your iPhone with your PC in the very normal way you sync both.

2. Look for the back-up of your files on your computer. You'll find it in the C drive of your computer, unless you have saved it manually somewhere else. Here go the paths:

For Windows XP or Vista: C:\Documents and Settings\USERNAME\Application Data\Apple Computer\MobileSync\Backup

For Mac: Library/Application Support/MobileSync/Backup

3. When you're successful in following the path, you will see a filename that has an .mdbackup extension. This is your back-up. Click on it.

4. Select the option that says Restore, and your files will be sent to the phone from your PC. Note that, restoring contacts is difficult in this case, and you have to get them in a file, and manually feed them. However, it's much better than losing 'em all mysteriously.

Method Two is always advisable for the DIY kinds, and is definitely the very first option (cheapest too) for iPhone users. However, for those who know their lost files don't exist in the iTunes backup folder, Method One is highly recommended. Some of them might cost a bomb, but the results are satisfactory. As the last bit of advice, always create a backup of your data in your iTunes folder to avoid all kinds of data loss.

Seven system functions

2012-01-14T05:45:00.003+07:00

Seven system functions

Knowledge Development: The Knowledge Development function involves learning activities, mostly on the emerging technology, but also on markets, networks, users etc. There are various types of learning activities, the most important categories being learning-by-searching and learning-by-doing. Knowledge Diffusion / Knowledge Exchange: The characteristic organisation structure of a Technological Innovation System is that of the network. Knowledge Diffusion activities involve partnerships between actors, for example technology developers, but also meetings like workshops and conferences. The important role of Knowledge Diffusion stems from Lundvall’s notion of interactive learning as the raison-d’être of any innovation system.^[20]Guidance of the Search: The Guidance of the Search function refers to activities that shape the needs, requirements and expectations of actors with respect to their (further) support of the emerging technology. A positive Guidance of the Search means a convergence of positive signals - expectations, promises, policy directives - in a particular direction of technology development. A healthy Technological Innovation System will strike a balance between creating and reducing variety.

Market Formation: Emerging technologies cannot be expected to compete with incumbent technologies. The Market Formation function involves activities that contribute to the creation of a demand for the emerging technology, for example by financially supporting the use of the emerging technology, or by taxing the use of competing technologies. Resource Mobilisation: Resource Mobilisation refers to the allocation of financial, material and human capital. Typical activities involved in this system function are investments and subsidies. The Resource Mobilisation function represents a basic economic variable. Support from Advocacy Coalitions: The rise of an emerging technology often leads to resistance from actors with interests in the incumbent energy system. In order for a Technological Innovation System to develop, other actors must counteract this inertia. This system function may be regarded as a special form of Guidance of the Search.

philosopher Martin Heidegger

2012-01-14T05:43:00.003+07:00

Many, such as the Luddites and prominent philosopher Martin Heidegger, hold serious, although not entirely deterministic reservations, about technology (see "The Question Concerning Technology^[45])". According to Heidegger scholars Hubert Dreyfus and Charles Spinosa, "Heidegger does not oppose technology. Darin Barney has written about technology's impact on practices of citizenship and democratic culture, suggesting that technology can be construed as (1) an object of political debate, (2) a means or medium of discussion, and (3) a setting for democratic deliberation and citizenship. What Project Socrates determined was that technology exploitation is the foundation of all competitive advantage and that the source of the US declining competitiveness was the fact that decision-making through the US both in the private and public sectors had switched from decision making that was based on technology exploitation (i.e., technology-based planning) to decision making that was based on money exploitation (i.e., economic-based planning) at the end of World War II.
Technology is properly defined as any application of science to accomplish a function. Project Socrates determined that to rebuild US competitiveness, decision making throughout the US had to readopt technology-based planning. To rebuild US competitiveness the US decision-makers needed adopt a form of technology-based planning that was far more advanced than that used by China and India.
Project Socrates determined that technology-based planning makes an evolutionary leap forward every few hundred years and the next evolutionary leap, the Automated Innovation Revolution, was poised to occur.

History Tehcnology

2012-01-14T05:42:00.001+07:00

The use of tools by early humans was partly a process of discovery, partly of evolution. ^[22] This era of stone tool use is called the Paleolithic, or "Old stone age", and spans all of human history up to the development of agriculture approximately 12,000 years ago.

To make a stone tool, a "core" of hard stone with specific flaking properties (such as flint) was struck with a hammerstone. The earliest stone tools were crude, being little more than a fractured rock. Fire

^[26] The exact date of its discovery is not known; evidence of burnt animal bones at the Cradle of Humankind suggests that the domestication of fire occurred before 1,000,000 BC;^[27] scholarly consensus indicates that Homo erectus had controlled fire by between 500,000 BC and 400,000 BC.Clothing and shelter

As the Paleolithic era progressed, dwellings became more sophisticated and more elaborate; as early as 380,000 BC, humans were constructing temporary wood huts.^[31]

Neolithic through classical antiquity (10,000BC – 300AD)

The invention of polished stone axes was a major advance because it allowed forest clearance on a large scale to create farms.

Metal tools

The advantages of copper tools over stone, bone, and wooden tools were quickly apparent to early humans, and native copper was probably used from near the beginning of Neolithic times (about 8000 BC).^[39]

Energy and transport

Meanwhile, humans were learning to harness other forms of energy. It didn't take long to discover that wheeled wagons could be used to carry heavy loads and fast (rotary) potters' wheels enabled early mass production of pottery. But it was the use of the wheel as a transformer of energy (through water wheels, windmills, and even treadmills) that revolutionized the application of nonhuman power sources.

Medieval and modern history (300 AD —)

Main articles: Medieval technology, Renaissance technology, Industrial Revolution, Second industrial revolution, Productivity improving technologies (historical), and Information Technology

Scientific advancement and the discovery of new concepts later allowed for powered flight, and advancements in medicine, chemistry, physics and engineering. The late 19th and early 20th centuries saw a revolution in transportation with the invention of the steam-powered ship, train, airplane, and automobile. In physics, the discovery of nuclear fission has led to both nuclear weapons and nuclear power. Complex manufacturing and construction techniques and organizations are needed to construct and maintain these new technologies, and entire industries have arisen to support and develop succeeding generations of increasingly more complex tools.

Technolgy Computer

2012-01-14T05:39:00.002+07:00

Technology is the making, usage, and knowledge of tools, machines, techniques, crafts, systems or methods of organization in order to solve a problem or perform a specific function. ^[1] The term can either be applied generally or to specific areas: examples include construction technology, medical technology, and information technology.
Technologies significantly affect human as well as other animal species' ability to control and adapt to their natural environments. The human species' use of technology began with the conversion of natural resources into simple tools. Technology has affected society and its surroundings in a number of ways. Various implementations of technology influence the values of a society and new technology often raises new ethical questions. Philosophical debates have arisen over the present and future use of technology in society, with disagreements over whether technology improves the human condition or worsens it. IBM and Sun operate more in the diversified computer systems industry which includes Information Technology (IT). The use of the term technology has changed significantly over the last 200 years. The meanings of technology changed in the early 20th century when American social scientists, beginning with Thorstein Veblen, translated ideas from the German concept of Technik into "technology." By the 1930s, "technology" referred not to the study of the industrial arts, but to the industrial arts themselves.^[4][7] The term is often used to imply a specific field of technology, or to refer to high technology or just consumer electronics, rather than technology as a whole.^[8]Tools and machines need not be material; virtual technology, such as computer software and business methods, fall under this definition of technology.^[10]
The word "technology" can also be used to refer to a collection of techniques. When combined with another term, such as "medical technology" or "space technology", it refers to the state of the respective field's knowledge and tools. "State-of-the-art technology" refers to the high technology available to humanity in any field.
Technology can be viewed as an activity that forms or changes culture.^[11][12] Not all technology enhances culture in a creative way; technology can also help facilitate political oppression and war via tools such as guns. As a cultural activity, technology predates both science and engineering, each of which formalize some aspects of technological endeavor.
The distinction between science, engineering and technology is not always clear. The development of technology may draw upon many fields of knowledge, including scientific, engineering, mathematical, linguistic, and historical knowledge, to achieve some practical result.
Technology is often a consequence of science and engineering — although technology as a human activity precedes the two fields.

CCNA 4 chapter 8

2012-01-13T21:58:00.002+07:00

1. What combination of IP address and wildcard mask should be used to specify only the last 8 addresses in the subnet 192.168.3.32/28?
192.168.3.32 0.0.0.7
192.168.3.32 0.0.0.15
192.168.3.40 0.0.0.7
192.168.3.40 0.0.0.15

2. Excessive broadcasts are generally a symptom of a problem at which layer?
physical
data link
network
transport
3.

Refer to the exhibit. Which three pieces of information can be determined by analyzing the output shown? (Choose three.)
A carrier detect signal is present.
Keepalives are being received successfully.
Default encapsulation is used on this serial link.
Packets passing this interface cannot exceed 1 KB in size.
The reliability of this link is very low.
The LCP negotiation phase is complete.
4. A network administrator has received complaints that users on a local LAN can retrieve e-mail from a remote e-mail server but are unable to open web pages on the same server. Services at which two layers of the OSI model should be investigated during the troubleshooting process? (Choose two.)
physical layer
data link layer
network layer
transport layer
application layer

5. When gathering symptoms for troubleshooting a network problem, which step could result in getting an external administrator involved in the process?
narrowing the scope
gathering symptoms from suspect devices
analyzing existing symptoms
determining ownership

6. Encapsulation errors from mismatched WAN protocols on a serial link between two routers indicate a problem at which OSI layer?
physical
data link
network
transport

7.

Refer to the exhibit. Users at Branch B are reporting trouble accessing a corporate website running on a server that is located at HQ. HQ and Branch A users can access the website. R3 is able to ping 10.10.10.1 successfully but not 10.10.10.2. The users at Branch B can access servers at Branch A. Which two statements are true aboutthe troubleshooting efforts? (Choose two.)
The web server should be tested for an application layer problem.
Frame Relay at R3 and R2 should be tested to narrow the scope of the problem.
The fact that users at Branch A are working normally proves that there is no problem at R2.
An ACL entry error could cause the failure at Layer 4 in either R3 or R2.
The successful ping from R3 to R1 proves that the WAN is functioning normally. Therefore, the problem has to be in the upper layers.

8. Which troubleshooting approach is suggested for dealing with a complex problem that is suspected of being caused by faulty network cabling?
bottom up
top down
divide and conquer
middle out

9. Users are complaining of very long wait times to access resources on the network. The show interface command reveals collision counts far above the network baseline. At which OSI layer should the administrator begin troubleshooting?
application
transport
network
data link
physical

10.

Refer to the exhibit. Users on the Internal LAN are unable to connect to the www server. The network administrator pings the server and verifies that NAT is functioning correctly. Which OSI layer should the administrator begin to troubleshoot next?
physical
data link
network
application

11. Which two statements are true concerning logical networking models? (Choose two.)
TCP/IP splits the lowest layer of the OSI model into two separate layers.
The top layer of the TCP/IP model combines the functions of the top three OSI layers.
Troubleshooting with the TCP/IP model requires different techniques than with the OSI model.
The network access layer is responsible for exchanging packets between devices on a TCP/IP network.
The Internet layer provides communication between applications, such as FTP, HTTP, and SMTP on separate hosts.
The TCP/IP network access layer corresponds to the OSI physical and data link layers.

12.

Refer to the exhibit. Which two steps should be taken during the process of creating network documentation? (Choose two.)
Record the information about the devices discovered in the Campus network only.
Record the information about the devices discovered in the entire network, including the remote locations.
Transfer any information about the devices from the network configuration table that corresponds to a component of the topology diagram.
Transfer only the Layer 2 and Layer 3 information about the devices from the network configuration table that corresponds to a component of the topology diagram.
Transfer the recorded information about the devices from the network configuration table gathered during peak network utilization that corresponds to a component of the topology diagram.

13. What is one example of a physical layer problem?
incorrect encapsulation
incorrect STP configuration
incorrect ARP mapping
incorrect clock rate

14. Clients across the company are reporting poor performance across all corporate applications running in the data center. Internet access and applications running across the corporate WAN are performing normally. The network administrator observes a continual broadcast of random meaningless traffic (jabber) on the application server LAN in the data center on a protocol analyzer. How should the administrator start troubleshooting?
The jabber in the data center indicates a local physical layer problem. Use the protocol analyzer to determine the source of the jabber, and then check for a recent NIC driver update or bad cabling.
Because all clients are experiencing application problems, the administrator should use a top-down approach with the application servers in the data center.
The scope of the problem indicates a likely routing or spanning-tree problem. Begin by checking routing tables, and follow up using appropriate STP show commands to find a loop if routing is working normally.
Poll the staff to determine if any recent changes have been made. Back out all the changes one by one until the error condition is fixed.

15. A technician has been asked to make several changes to the configuration and topology of a network and then determine the outcome of the changes. What tool can be used to determine the overall effect caused by the changes?
baselining tool
knowledge base
protocol analyzer
cable tester

16. A technician has been asked to troubleshoot an existing switched network but is unable to locate documentation for the VLAN configuration. Which troubleshooting tool allows the technician to map and discover VLAN and port assignments?
cable analyzer
network analyzer
protocol analyzer
knowledge base

17. Which two pieces of information are typically found on a logical network diagram? (Choose two.)
cable types
connector types
interface identifiers
DLCI for virtual circuits
operating system versions

18. Which two components should be taken into consideration when establishing a network baseline? (Choose two.)
information about the network design
IP addressing allocation on the network
requirements about the service provider setup
requirements for access control lists to regulate traffic
expected performance under normal operating conditions

19. Which three approaches should be used when attempting to gather data from users for troubleshooting? (Choose three.)
Determine fault.
Get to know the user to build trust.
Obtain information by asking simple pertinent questions.
Impress the user with use of technical language and skills.
Determine if the problem is related to time or a specific event.
Determine if the user can re-create the problem or events leading to the problem.

20. Information about which OSI layers of connected Cisco devices can be verified with the show cdp neighbors command?
All layers
Layer 1, Layer 2, and Layer 3
Layer 1, Layer 2, Layer 3, and Layer 4
Layer 6 and Layer 7

CCNA 4 chapter 7

2012-01-13T21:57:00.002+07:00

1.

Refer to the exhibit. Traffic exiting R1 is failing translation. What part of the configuration is most likely incorrect?
ip nat pool statement
access-list statement
ip nat inside is on the wrong interface
interface s0/0/2 should be a private IP address

2.

Refer to the exhibit. What is the purpose of the command marked with an arrow shown in the partial configuration output of a Cisco broadband router?
defines which addresses can be translated
defines which addresses are allowed into the router
defines which addresses are assigned to a NAT pool
defines which addresses are allowed out of the router

3. How many bits of an IPv6 address are used to identify the interface ID?
32
48
64
128

4.Refer to the exhibit. How many IPv6 broadcast domains exist in this topology?
0
1
2
3
4

5.

Refer to the exhibit. Which two addresses could be assigned to traffic leaving S0 as a result of the statement ip nat pool Tampa 179.9.8.96 179.9.8.111 netmask 255.255.255.240? (Choose two.)
10.0.0.125
179.9.8.95
179.9.8.98
179.9.8.101
179.9.8.112

6.

Refer to the exhibit. A network technician determines DHCP clients are not working properly. The clients are receiving IP configuration information from a DHCP server configured on the router but cannot access the Internet. From the output in the graphic, what is the most likely problem?
The DHCP server service is not enabled.
The inside interface for DCHP is not defined.
The DHCP pool is not bound to the interface.
The pool does not have a default router defined for the clients.
All the host addresses have been excluded from the DHCP pool.

7. Your organization is issued the IPv6 prefix of 2001:0000:130F::/48 by your service provider. With this prefix, how many bits are available for your organization to create subnetworks?
8
16
80
128

8. After activating IPv6 routing on a Cisco router and programming IPv6 addresses on multiple interfaces, what is the remaining step to activate RIPng?
Enter the interface programming mode for each IPv6 interface and enable IPng RIP.
Enter the ipv6 router rip name command and then use network statements to activate RIPng on the interfaces.
Enter the router rip command, and then activate RIPng using the version command. RIPng then automatically runs on all IPv6 interfaces.
Enter the interface programming mode for each IPv6 interface and enable the multicast group FF02::9, and then activate RIPng globally using the ipv6 router rip name command.

9.

Refer to the exhibit. IPv6 address 2006:1::1/64 eui-64 has been configured on the router FastEthernet0/0 interface. Which statement accurately describes the EUI-64 identifier configuration?
It will randomly generate a 64 bit interface ID.
It will assign an address from the pool of IPv6 private addresses to the interface.
It will assign only the registry prefix of the IPv6 Global Unicast address to the interface.
The configuration will derive the interface portion of the IPv6 address from the MAC address of the interface.

10. What is true regarding the differences between NAT and PAT?
PAT uses the word "overload" at the end of the access-list statement to share a single registered address.
Static NAT allows an unregistered address to map to multiple registered addresses.
Dynamic NAT allows hosts to receive the same global address each time external access is required.
PAT uses unique source port numbers to distinguish between translations.

11.

Refer to the exhibit. The FTP server has an RFC 1918 private address. Users on the Internet need to connect to the FTP server on the Fa0/0 LAN of R1. Which three configurations must be completed on R1? (Choose three.)
dynamic NAT
NAT with overloading
open port 20
open port 21
open port 23
NAT with port forwarding

12.

Refer to the exhibit. On the basis of the configuration shown, how should the pool of the excluded addresses be assigned to key hosts on the network, such as router interfaces, printers, and servers?
The addresses are statically assigned by the network administrator.
The DHCP server dynamically assigns the addresses.
The addresses must be listed under the DHCP pool of addresses before they are available for static assignment.
The addresses must be listed under the DHCP pool of addresses before they are available for dynamic assignment.

13.

Refer to the exhibit. A technician used SDM to enter the NAT configuration for a Cisco router. Which statement correctly describes the result of the configuration?
A user on the inside sees web traffic coming from 192.168.1.3 using port 8080.
The address 172.16.1.1 is translated into an address from the pool beginning with 192.168.1.3.
A user on the outside network sees a request addressed from 192.168.1.3 using port 80.
A user on the outside must address traffic to port 8080 to reach the address 172.16.1.1.

14.

Refer to the exhibit. According to the output, how many addresses have been successfully assigned or renewed by this DHCP server?
1
6
7
8
9

15. What are two benefits of NAT? (Choose two.)
It saves public IP addresses.
It adds a degree of privacy and security to a network.
It increases routing performance.
It makes troubleshooting routing issues easier.
It makes tunneling with IPsec less complicated.

16.

Refer to the exhibit. R1 is performing NAT for the 10.1.1.0/24 network, and R2 is performing NAT for the 192.168.1.2/24 network. What would be valid destination IP address for HostA to put in its IP header when communicating with the web server?
10.1.1.1
172.30.20.2
192.168.1.2
255.255.255.255

17.

Refer to the exhibit. Which two statements about the configuration are true? (Choose two.)
Traffic from the 10.1.1.0 network will be translated.
Traffic from the 209.165.200.0 network will be translated.
Permitted traffic gets translated to a single inside global IP address.
A pool of inside global IP addresses from the 10.1.1.0 network will be used for translation.
External users from the 209.165.200.0 network can reach private addresses on the 10.1.1.0 and 10.1.2.0 networks.

18. What type of NAT should a network administrator use to ensure that a web server on the inside network is always available to the outside network?
NAT overload
static NAT
dynamic NAT
PAT

19.

Refer to the exhibit. Which address or addresses represent the inside global address?
10.1.1.2
192.168.0.100
209.165.20.25
any address in the 10.1.1.0 network

20. A technician has been told by a supervisor to always clear any dynamic translations before attempting to troubleshoot a failed NAT connection. Why has the supervisor issued these instructions?
The supervisor wants to clear any confidential information that may be seen by the technician.
Because entries can be cached for long periods of time, the supervisor wants to prevent decisions being made based on old data.
The translation table may be full and is unable to make new translations until space is available.
Clearing the translations causes the starting configuration to be reread and may correct translation problems that have occurred.

21. A network administrator wants to connect two IPv6 islands. The easiest way is through a public network that uses only IPv4 equipment. What simple solution solves the problem?
Replace the devices on the public network with devices that support IPv6.
Configure RIPng on the border routers of each IPv6 island.
Configure the routers to take advantage of dual-stack technology.
Use tunneling to encapsulate the IPv6 traffic in the IPv4 protocol.

CCNA 4 chapter 6

2012-01-13T21:55:00.003+07:00

1. Which two protocols can be used to encapsulate traffic that is traversing a VPN tunnel? (Choose two.)
ATM
CHAP
IPsec
IPX
MPLS
PPTP

2. What are the three main functions of a secure VPN? (Choose three.)
accounting
authentication
authorization
data availability
data confidentiality
data integrity

3. Data confidentiality through a VPN can be enhanced through the use of which three encryption protocols? (Choose three.)
AES
DES
AH
hash
MPLS
RSA

4. While monitoring traffic on a cable network, a technician notes that data is being transmitted at 38 MHz. Which statement describes the situation observed by the technician?
Data is being transmitted from the subscriber to the headend.
Data is flowing downstream.
Cable television transmissions are interfering with voice and data transmissions.
The system is experiencing congestion in the lower frequency ranges.

5. Which two statements are valid solutions for a cable ISP to reduce congestion for users? (Choose two.)
use higher RF frequencies
allocate an additional channel
subdivide the network to reduce users on each segment
reduce the length of the local loop to 5.5 kilometers or less
use filters and splitters at the customer site to separate voice from data traffic

6. Data confidentiality through a VPN is achieved through which two methods? (Choose two.)
digital certificates
encryption
encapsulation
hashing
passwords

7. What two protocols provide data authentication and integrity for IPsec? (Choose two.)
AH
L2TP
ESP
GRE
PPTP

8. Which two methods could an administrator use to authenticate users on a remote access VPN? (Choose two.)
digital certificates
ESP
hashing algorithms
smart cards
WPA

9. Which is an example of symmetric-key encryption?
Diffie-Hellman
digital certificate
pre-shared key
RSA signature

10.

Refer to the exhibit. A teleworker is connected over the Internet to the HQ Office. What type of secure connection can be established between the teleworker and the HQ Office?
a GRE tunnel
a site-to-site VPN
a remote-access VPN
the user must be at the office location to establish a secure connection

11. After conducting research to learn about common remote connection options for teleworkers, a network administrator has decided to implement remote access over broadband to establish VPN connections over the public Internet. What is the result of this solution?
A reliable connection is established at greater speeds than what is offered from dialup over POTS. Security is increased, but username and password information are sent in plain text.
The connection has increased security and reliable connectivity. Users need a remote VPN router or VPN client software.
Security and reliability are increased at a substantial loss in throughput, which is considered acceptable when supporting a single user environment.
Reliability and security are increased without the need for additional equipment, when compared to dialup connections using POTS.

12. Which two statements about DSL are true? (Choose two.)
users are on a shared medium
uses RF signal transmission
local loop can be up to 3.5 miles (5.5km)
physical and data link layers are defined by DOCSIS
user connections are aggregated at a DSLAM located at the CO

13. A company is using WiMAX to provide access for teleworkers. What home equipment must the company provide at the teleworker’s site?
a WiMAX tower
a one-way multicast satellite
a WiMAX receiver
an access point connected to the company WLAN

14. A technician has been asked to configure a broadband connection for a teleworker. The technician has been instructed that all uploads and downloads for the connection must use existing phone lines. Which broadband technology should be used?
cable
DSL
ISDN
POTS

15. Which two Layer 1 requirements are outlined in the Data-over-Cable Service Interface Specification (DOCSIS)? (Choose two.)
channel widths
access method
maximum data rate
modulation techniques
compression techniques

16.

Refer to the exhibit. All users have a legitimate purpose and the necessary permissions to access the Corporate network. Based on the topology shown, which locations are able to establish VPN connectivity with the Corporate network?
Locations C, D, and E can support VPN connectivity. Locations A and B require an additional PIX Firewall appliance installed on the edge of the network.
Locations C and E can support VPN connectivity. Locations A, B, and D require an additional PIX Firewall appliance installed on the edge of the network.
Locations A, B, D, and E can support VPN connectivity. Location C requires an additional router on the edge of the network.
All locations can support VPN connectivity.

17. Which two features can be associated with the Worldwide Interoperability for Microwave Access (WiMAX) telecommunication technology? (Choose two.)
supports municipal wireless networks utilizing mesh technologies
covers areas as large as 7,500 square kilometers
supports point-to-point links, but not full mobile cellular-type access
connects directly to the Internet through high-bandwidth connections
operates at lower speeds than Wi-Fi, but supports many more users

18.

Refer to the exhibit. A VPN tunnel has been established between the HQ Office and the Branch Office over the public Internet. Which three mechanisms are required by the devices on each end of the VPN tunnel to protect the data from being intercepted and modified? (Choose three.)
The devices must use a dedicated Layer 2 connection.
The devices must have the VPN client software installed.
The two parties must inspect the traffic against the same ACLs.
The two parties must establish a secret key used by encryption and hash algorithms.
The two parties must agree on the encryption algorithm to be used over the VPN tunnel.
The devices must be authenticated before the communication path is considered secure.

19. Which statement describes cable?
Delivering services over a cable network requires downstream frequencies in the 50 to 860 MHz range, and upstream frequencies in the 5 to 42 MHz range.
The cable subscriber must purchase a cable modem termination system (CMTS)
Each cable subscriber has dedicated upstream and downstream bandwidth.
Cable subscribers may expect up to 27 Mbps of bandwidth on the upload path.

CCNA 4 chapter 5

2012-01-13T21:53:00.001+07:00

1. The following commands were entered on a router:
Router(config)# access-list 2 deny 172.16.5.24
Router(config)# access-list 2 permit any
The ACL is correctly applied to an interface. What can be concluded about this set of commands?
The wildcard mask 0.0.0.0 is assumed.
The access list statements are misconfigured.
All nodes on the 172.16.0.0 network will be denied access to other networks.
No traffic will be allowed to access any nodes or services on the 172.16.0.0 network.

2. Interface s0/0/0 already has an IP ACL applied inbound. What happens when the network administrator attempts to apply a second inbound IP ACL?
The second ACL is applied to the interface, replacing the first.
Both ACLs are applied to the interface.
The network administrator receives an error.
Only the first ACL remains applied to the interface.
3. Which two statements are correct about extended ACLs? (Choose two)
Extended ACLs use a number range from 1-99.
Extended ACLs end with an implicit permit statement.
Extended ACLs evaluate the source and destination addresses.
Port numbers can be used to add greater definition to an ACL.
Multiple ACLs can be placed on the same interface as long as they are in the same direction.

4. Which benefit does an extended ACL offer over a standard ACL?
Extended ACLs can be named, but standard ACLs cannot.
Unlike standard ACLs, extended ACLS can be applied in the inbound or outbound direction.
Based on payload content, an extended ACL can filter packets, such as information in an e-mail or instant message.
In addition to the source address, an extended ACL can also filter on destination address, destination port, and source port.

5.

Refer to the exhibit. How will Router1 treat traffic matching the time-range requirement of EVERYOTHERDAY?
TCP traffic entering fa0/0 from 172.16.1.254/24 destined to the 10.1.1.0/24 network is permitted.
TCP traffic entering fa0/0 from 10.1.1.254/24 destined to the 172.16.1.0/24 network is permitted.
Telnet traffic entering fa0/0 from 172.16.1.254/24 destined to the 10.1.1.0/24 network is permitted.
Telnet traffic entering fa0/0 from 10.1.1.254/24 destined to the 172.16.1.0/24 network is permitted.

6. Which three statements describe ACL processing of packets? (Choose three.)
An implicit deny any rejects any packet that does not match any ACL statement.
A packet can either be rejected or forwarded as directed by the statement that is matched.
A packet that has been denied by one statement can be permitted by a subsequent statement.
A packet that does not match the conditions of any ACL statements will be forwarded by default.
Each statement is checked only until a match is detected or until the end of the ACL statement list.
Each packet is compared to the conditions of every statement in the ACL before a forwarding decision is made.

7.

Refer to the exhibit. The administrator wishes to block web traffic from 192.168.1.50 from reaching the default port of the web service on 192.168.3.30. To do this, the access control list name is applied inbound on the router R1 LAN interface. After testing the list, the administrator has noted that the web traffic remains successful. Why is web traffic reaching the destination?
Web traffic does not use port 80 by default.
The access list is applied in the wrong direction.
The access list needs to be placed closer to the destination, on R3.
The range of source addresses specified in line 10 does not include host 192.168.1.50.

8. Which feature will require the use of a named ACL rather than a numbered ACL?
the ability to filter traffic based on a specific protocol
the ability to filter traffic based on an entire protocol suite and destination
the ability to specify source and destination addresses to use when identifying traffic
the ability to edit the ACL and add additional statements in the middle of the list without removing and re-creating the list

9. Which two statements are true regarding the significance of the access control list wildcard mask 0.0.0.7? (Choose two.)
The first 29 bits of a given IP address will be ignored.
The last 3 bits of a given IP address will be ignored.
The first 32 bits of a given IP address will be checked.
The first 29 bits of a given IP address will be checked.
The last 3 bits of a given IP address will be checked.

10. Where should a standard access control list be placed?
close to the source
close to the destination
on an Ethernet port
on a serial port

11. How do Cisco standard ACLs filter traffic?
by destination UDP port
by protocol type
by source IP address
by source UDP port
by destination IP address

12. Which two statements are true regarding named ACLs? (Choose two.)
Only named ACLs allow comments.
Names can be used to help identify the function of the ACL.
Named ACLs offer more specific filtering options than numbered ACLs.
Certain complex ACLs, such as reflexive ACLs, must be defined with named ACLs.
More than one named IP ACL can be configured in each direction on a router interface.

13.

Refer to the exhibit. What will be the effect of the configuration that is shown?
Users attempting to access hosts in the 192.168.30.0/24 network will be required to telnet to R3.
Hosts connecting to resources in the 191.68.30.0/24 network have an idle timeout of 15 minutes.
Anyone attempting to telnet into R3 will have an absolute time limit of five minutes.
Telnet access to R3 will only be permitted on Serial 0/0/1.

14.

Refer to the exhibit. An administrator has configured two access lists on R1. The list inbound on the serial interface is named Serial and the list inbound on the LAN interface is named LAN. What affect will be produced by the access control lists?
PC1 will be able to telnet to PC3.
R3 will not be able to communicate with PC1 and PC3.
PC3 cannot telnet to R3 and cannot communicate with PC1.
PC1 will not be able to telnet to R3 and PC3 will not be able to communicate with PC1.

15. Which two statements are true regarding the following extended ACL? (Choose two.)
access-list 101 deny tcp 172.16.3.0 0.0.0.255 any eq 20
access-list 101 deny tcp 172.16.3.0 0.0.0.255 any eq 21
access-list 101 permit ip any any
FTP traffic originating from network 172.16.3.0/24 is denied.
All traffic is implicitly denied.
FTP traffic destined for the 172.16.3.0/24 network is denied.
Telnet traffic originating on network 172.16.3.0/24 is denied.
Web traffic originating from 172.16.3.0 is permitted.

16. Which statement about standard ACLs is true?
Standard ACLS must be numbered and cannot be named.
They should be placed as close to the destination as possible.
They can filter based on source and destination address as well as on source and destination port.
When applied to an outbound interface, incoming packets are processed before they are routed to the outbound interface.

17.

Refer to the exhibit. Which statement is true about ACL 110 if ACL 110 is applied in the inbound direction on S0/0/0 of R1?
It will deny TCP traffic to the Internet if the traffic is sourced from the 172.22.10.0/24 network.
It will not allow TCP traffic coming from the Internet to enter the network 172.22.10.0/24.
It will allow any TCP traffic from the Internet to enter the network 172.22.10.0/24.
It will permit any TCP traffic that originated from network 172.22.10.0/24 to return inbound on the S0/0/0 interface.

18. Which three parameters can ACLs use to filter traffic? (Choose three.)
packet size
protocol suite
source address
destination address
source router interface
destination router interface

19.

Refer to the exhibit. How does this access list process a packet with the source address 10.1.1.1 and a destination of 192.168.10.13?
It is allowed because of the implicit deny any.
It is dropped because it does not match any of the items in the ACL.
It is allowed because line 10 of the ACL allows packets to 192.168.0.0/16.
It is allowed because line 20 of the ACL allows packets to the host 192.168.10.13.

20. By default, how is IP traffic filtered in a Cisco router?
blocked in and out of all interfaces
blocked on all inbound interfaces, but permitted on all outbound interfaces
permitted in and out of all interfaces
blocked on all outbound interfaces, but permitted on all inbound interfaces

21.

Refer to the exhibit. When creating an extended ACL to deny traffic from the 192.168.30.0 network destined for the Web server 209.165.201.30, where is the best location for applying the ACL?
ISP Fa0/0 outbound
R2 S0/0/1 inbound
R3 Fa0/0 inbound
R3 S0/0/1 outbound

22.

Refer to the exhibit. ACL 120 is configured inbound on the serial0/0/0 interface on router R1, but the hosts on network 172.11.10.0/24 are able to telnet to network 10.10.0.0/16. On the basis of the provided configuration, what should be done to remedy the problem?
Apply the ACL outbound on the serial0/0/0 interface on router R1.
Apply the ACL outbound on the FastEthernet0/0 interface on router R1.
Include the established keyword at the end of the first line in the ACL.
Include a statement in the ACL to deny the UDP traffic that originates from 172.11.10.0/24 network.

23. A network administrator needs to allow traffic through the firewall router for sessions that originate from within the company network, but the administrator must block traffic for sessions that originate outside the network of the company. What type of ACL is most appropriate?
dynamic
port-based
reflexive
time-based

24. A technician is creating an ACL and needs a way to indicate only the subnet 172.16.16.0/21. Which combination of network address and wildcard mask will accomplish the desired task?
172.16.0.0 0.0.255.255
127.16.16.0 0.0.0.255
172.16.16.0 0.0.7.255
172.16.16.0 0.0.15.255
172.16.16.0 0.0.255.255

25. Which three items must be configured before a dynamic ACL can become active on a router? (Choose three.)
extended ACL
reflexive ACL
console logging
authentication
Telnet connectivity
user account with a privilege level of 15

CCNA 4 chapter 4

2012-01-13T21:52:00.001+07:00

1. Which two statements are true regarding network security? (Choose two.)
Securing a network against internal threats is a lower priority because company employees represent a low security risk.
Both experienced hackers who are capable of writing their own exploit code and inexperienced individuals who download exploits from the Internet pose a serious threat to network security.
Assuming a company locates its web server outside the firewall and has adequate backups of the web server, no further security measures are needed to protect the web server because no harm can come from it being hacked.
Established network operating systems like UNIX and network protocols like TCP/IP can be used with their default settings because they have no inherent security weaknesses.
Protecting network devices from physical damage caused by water or electricity is a necessary part of the security policy.

2. Which two statements are true about network attacks? (Choose two.)
Strong network passwords mitigate most DoS attacks.
Worms require human interaction to spread, viruses do not.
Reconnaissance attacks are always electronic in nature, such as ping sweeps or port scans.
A brute-force attack searches to try every possible password from a combination of characters.
Devices in the DMZ should not be fully trusted by internal devices, and communication between the DMZ and internal devices should be authenticated to prevent attacks such as port redirection.

3. Users are unable to access a company server. The system logs show that the server is operating slowly because it is receiving a high level of fake requests for service. Which type of attack is occurring?
reconnaissance
access
DoS
worm
virus
Trojan horse
4.

Refer to the exhibit. What is the purpose of the "ip ospf message-digest-key 1 md5 cisco" statement in the configuration?
to specify a key that is used to authenticate routing updates
to save bandwidth by compressing the traffic
to enable SSH encryption of traffic
to create an IPsec tunnel

5. What are three characteristics of a good security policy? (Choose three.)
It defines acceptable and unacceptable use of network resources.
It communicates consensus and defines roles.
It is developed by end users.
It is developed after all security devices have been fully tested.
It defines how to handle security incidents.
It should be encrypted as it contains backups of all important passwords and keys.

6. Intrusion detection occurs at which stage of the Security Wheel?
securing
monitoring
testing
improvement
reconnaissance

7. Which two objectives must a security policy accomplish? (Choose two.)
provide a checklist for the installation of secure servers
describe how the firewall must be configured
document the resources to be protected
identify the security objectives of the organization
identify the specific tasks involved in hardening a router

8. Which two statements define the security risk when DNS services are enabled on the network? (Choose two.)
By default, name queries are sent to the broadcast address 255.255.255.255.
DNS name queries require the ip directed-broadcast command to be enabled on the Ethernet interfaces of all routers.
Using the global configuration command ip name-server on one router enables the DNS services on all routers in the network.
The basic DNS protocol does not provide authentication or integrity assurance.
The router configuration does not provide an option to set up main and backup DNS servers.

9.

Refer to the exhibit. Security Device Manager (SDM) has been used to configure a required level of security on the router. What would be accomplished when the SDM applies the next step on the security problems that are identified on the router?
SDM will automatically invoke the AutoSecure command.
SDM will generate a report that will outline the proper configuration actions to alleviate the security issues.
SDM will create a configuration file that can be copy and pasted into the router to reconfigure the services.
SDM will reconfigure the services that are marked in the exhibit as “fix it” to apply the suggested security changes.

10. An IT director has begun a campaign to remind users to avoid opening e-mail messages from suspicious sources. Which type of attack is the IT director trying to protect users from?
DoS
DDoS
virus
access
reconnaissance

11. What are two benefits of using Cisco AutoSecure? (Choose two.)
It gives the administrator detailed control over which services are enabled or disabled.
It offers the ability to instantly disable non-essential system processes and services.
It automatically configures the router to work with SDM.
It ensures the greatest compatibility with other devices in your network.
It allows the administrator to configure security policies without having to understand all of the Cisco IOS software features.

12. Which statement is true about Cisco Security Device Manager (SDM)?
SDM can run only on Cisco 7000 series routers.
SDM can be run from router memory or from a PC.
SDM should be used for complex router configurations.
SDM is supported by every version of the Cisco IOS software.

13. The Cisco IOS image naming convention allows identification of different versions and capabilities of the IOS. What information can be gained from the filename c2600-d-mz.121-4? (Choose two.)
The "mz" in the filename represents the special capabilities and features of the IOS.
The file is uncompressed and requires 2.6 MB of RAM to run.
The software is version 12.1, 4th revision.
The file is downloadable and 121.4MB in size.
The IOS is for the Cisco 2600 series hardware platform.

14.

Refer to the exhibit. The network administrator is trying to back up the Cisco IOS router software and receives the output shown. What are two possible reasons for this output? (Choose two.)
The Cisco IOS file has an invalid checksum.
The TFTP client on the router is corrupt.
The router cannot connect to the TFTP server.
The TFTP server software has not been started.
There is not enough room on the TFTP server for the software.

15. The password recovery process begins in which operating mode and using what type of connection? (Choose two.)
ROM monitor
boot ROM
Cisco IOS
direct connection through the console port
network connection through the Ethernet port
network connection through the serial port

16.

Refer to the exhibit. Security Device Manager (SDM) is installed on router R1. What is the result of opening a web browser on PC1 and entering the URL https://192.168.10.1?
The password is sent in plain text.
A Telnet session is established with R1.
The SDM page of R1 appears with a dialog box that requests a username and password.
The R1 home page is displayed and allows the user to download Cisco IOS images and configuration files.

17.

Refer to the exhibit. A network administrator is trying to configure a router to use SDM, but it is not functioning correctly. What could be the problem?
The privilege level of the user is not configured correctly.
The authentication method is not configured correctly.
The HTTP server is not configured correctly.
The HTTP timeout policy is not configured correctly.

18. Which step is required to recover a lost enable password for a router?
Set the configuration register to bypass the startup configuration.
Copy the running configuration to the startup configuration.
Reload the IOS from a TFTP server from ROMMON.
Reconfigure the router using setup mode.

19. What is the best defense for protecting a network from phishing exploits?
Schedule antivirus scans.
Schedule antispyware scans .
Schedule training for all users.
Schedule operating systems updates.

20. Which two conditions should the network administrator verify before attempting to upgrade a Cisco IOS image using a TFTP server? (Choose two.)
Verify the name of the TFTP server using the show hosts command.
Verify that the TFTP server is running using the tftpdnld command.
Verify that the checksum for the image is valid using the show version command.
Verify connectivity between the router and TFTP server using the ping command.
Verify that there is enough flash memory for the new Cisco IOS image using the show flash command.

21.

Refer to the exhibit. What is accomplished when both commands are configured on the router?
The commands filter UDP and TCP traffic coming to the router.
The commands disable any TCP or UDP request sent by the routing protocols.
The commands disable the services such as echo, discard, and chargen on the router to prevent security vulnerabilities.
The commands disable the BOOTP and TFTP server services to prevent security vulnerabilities.

22. Which two statements regarding preventing network attacks are true? (Choose two.)
The default security settings for modern server and PC operating systems can be trusted to have secure default security settings.
Intrusion prevention systems can log suspicious network activity, but there is no way to counter an attack in progress without user intervention.
Physical security threat mitigation consists of controlling access to device console ports, labeling critical cable runs, installing UPS systems, and providing climate control.
Phishing attacks are best prevented by firewall devices.
Changing default usernames and passwords and disabling or uninstalling unnecessary services are aspects of device hardening.

CCNA 4 chapter 3

2012-01-13T21:49:00.001+07:00

1. Which three actions might a Frame Relay switch perform when it detects an excessive build-up of frames in its queue? (Choose three.)
puts a hold on accepting frames in excess of the CIR
drops frames from the queue that have the DE bit set
reduces the number of frames it sends over the link
re-negotiates flow control with the connected device
sets the FECN bit on all frames it receives on the congested link
sets the BECN bit on all frames it places on the congested link

2. Which best describes the benefit of using Frame Relay as opposed to a leased line or ISDN service?
Customers can define their virtual circuit needs in far greater combinations, with increments as small as 64 kbps.
Customers pay for an end-to-end connection that includes the local loop and the network link.
Customers only pay for the local loop and the bandwidth they purchase from the network provider.
Connecting new sites requires new lower cost circuit installations when compared to ISDN dialup costs or adding additional hardware for leased service.

3.

Refer to the exhibit. Router R1 has been configured for Frame Relay connectivity to routers R2 and R3. What configuration option should be configured on the R2 and R3 serial interfaces in order for all routers to ping each other successfully?
R2(config-if)# frame-relay interface-dlci 201 broadcast
R3(config-if)# frame-relay interface-dlci 301 broadcast
R2(config-if)# frame-relay map ip 10.1.1.1 201 broadcast
R3(config-if)# frame-relay map ip 10.1.1.1 301 broadcast
R2(config-if)# frame-relay map ip 10.1.1.3 201 broadcast
R3(config-if)# frame-relay map ip 10.1.1.2 301 broadcast
R2(config-if)# frame-relay map ip 10.1.1.1 201 broadcast
R2(config-if)# frame-relay map ip 10.1.1.3 201 broadcast
R3(config-if)# frame-relay map ip 10.1.1.1 301 broadcast
R3(config-if)# frame-relay map ip 10.1.1.2 301 broadcast
4. Which two items allow the router to map data link layer addresses to network layer addresses in a Frame Relay network? (Choose two.)
ARP
RARP
Proxy ARP
Inverse ARP
LMI status messages
ICMP

5.

Refer to the exhibit. Which two outcomes occur from the configuration shown? (Choose two.)
The broadcasts will be forwarded to 10.1.1.1.
The router will use DLCI 22 to forward data to 10.1.1.1.
DLCI 22 will replace the MAC address in the ARP table for entry 10.1.1.1
Inverse-ARP will now add an entry for 10.1.1.1 into the Frame Relay map table using DLCI 22.
Frames sent by 10.1.1.1 arriving on interface serial 0/0/0 of RT_1 will have a data link layer address of 22.

6.

Refer to the exhibit. What can be determined about the Frame Relay switch from the output shown?
It is currently not transmitting data.
It is in the process of establishing the PVC.
It has put a hold on processing frames in excess of the CIR.
It is experiencing congestion.

7.

Refer to the exhibit. What can be determined from the output?
Serial 0/0/0 has been configured with an DLCI of 201.
Serial 0/0/0 has the feature frame-relay inverse-arp enabled.
Serial 0/0/0 has been configured with an IP address of 172.16.4.3.
Serial 0/0/0 has been configured with the command frame-relay map ip 172.16.4.3 201 broadcast.

8.

Refer to the exhibit. What effect does the point-to-point configuration on subinterface S0/0.110 have on the operation of the router?
It helps to conserve IP addresses.
It establishes multiple PVC connections to multiple physical interfaces.
It eliminates split horizon issues without increasing the likelihood of routing loops.
It requires the configuration of the encapsulation command on the subinterface.

9.

Refer to the exhibit. Which statement explains why the Frame Relay connection between R1 and R2 is failing?
Split horizon must be disabled.
The LMI type must be specified.
Logical subinterfaces must be used instead.
The frame-relay map commands are using incorrect DLCIs.

10. What best describes the use of a data-link connection identifier (DLCI)?
local address identifying a destination router across a Frame Relay network
locally significant address used to identify a virtual circuit
logical address identifying the interface between a router and a Frame Relay switch
logical address used to identify the DCE

11.

Refer to the exhibit. Router R1 has been configured for Frame Relay connectivity to routers R2 and R3. Which set of configuration options for routers R2 and R3 would provide each router connectivity to R1?
R2(config)# interface serial0/0/1
R2(config-if)# frame-relay map ip 10.1.1.1 102
R3(config)# interface serial0/0/1
R3(config-if)# frame-relay map ip 10.1.2.1 103
R2(config)# interface serial0/0/1
R2(config-if)# frame-relay map ip 10.1.1.1 102
R2(config-if)# frame-relay map ip 10.1.2.3 301
R3(config)# interface serial0/0/1
R3(config-if)# frame-relay map ip 10.1.2.1 103
R3(config-if)# frame-relay map ip 10.1.1.2 201
R2(config)# interface serial0/0/1.201 point-to-point
R2(config-if)# no frame-relay invers-arp
R3(config)# interface serial0/0/1.301 point-to-point
R3(config-if)# no frame-relay invers-arp
R2(config)# interface serial0/0/1.201 point-to-point
R2(config-if)# frame-relay interface-dlci 201
R3(config)# interface serial0/0/1.301 point-to-point
R3(config-if)# frame-relay interface-dlci 301

12.

Refer to the exhibit. Frame Relay connectivity has been configured in the network and OSPF is used as the routing protocol. Router R1 can successfully ping the router R2 serial interface. When R1 attempts to ping network 192.168.3.0/24 the ping fails. What additional configuration should be applied on all routers to remedy the problem?
Add the broadcast keyword in the Frame Relay map command on both routers.
Issue the frame-relay interface-dlci command in addition to the frame-relay map command on both router interfaces.
Remove the frame-relay map command and replace with the frame-relay interface-dlci command on both router interfaces.
Apply the no frame-relay inverse-arp command on both router interfaces.

13. Which statement about Frame Relay subinterfaces is correct?
Multipoint interfaces will automatically forward routing broadcasts but will consume more IP addresses than point-to-point subinterfaces will consume.
Point-to-point subinterfaces act like leased lines and eliminate split-horizon routing issues.
Interfaces with multiple PVCs require a separate subinterface for each PVC.
Multipoint configurations cannot use subinterfaces.

14.

Refer to the exhibit. What can be determined about the configuration of router R1 from the exhibited output?
LMI updates are not being received properly.
The LMI type for the Serial 0/0/0 interface has been left to its default configuration.
Cisco HDLC is used as a Layer 2 encapsulation protocol on the Serial 0/0/0 interface.
The Serial 0/0/0 interface has been configured as a data communications equipment device.

15. What is created between two DTEs in a Frame Relay network?
ISDN circuit
limited access circuit
switched parallel circuit
virtual circuit

16. Which Frame Relay topology is a compromise of costs, reliability, and complexity when the WAN contains one headquarters site, 40 regional sites, and several sites within each regional site?
star
full mesh
partial mesh
point-to-multipoint
point-to-point

17.

Refer to the exhibit. A ping is sent to address 192.168.50.10 from the Peanut router. Which DLCI will be used to send the ping?
110
115
220
225

18. What two methods does Frame Relay technology use to process frames that contain errors? (Choose two.)
Frame Relay services depend on the upper layer protocols to handle error recovery.
It requires the receiving device to request that the sender retransmit erroneous frames.
FECN, BECN, and DE bits are set in the frames to minimize errors.
The receiving device drops any frames that contain errors without notifying the sender.
The frame relay switch notifies the sender that errors were detected.

19.

Refer to the exhibit. Which two statements are true given the output shown? (Choose two.)
The IP address of the local Frame Relay interface is 172.16.1.4.
The local DLCI number is 401.
Inverse ARP is being used on this connection.
This interface is in the active state and in the process of negotiating configuration parameters.
Multicast is not enabled on this connection.

20.

Refer to the exhibit. What can be known about the configuration of router R1 from the output?
The Frame Relay LMI DLCI has been incorrectly configured as DLCI 1023.
The Frame Relay LMI type has been changed from its default.
The Serial 0/0/0 interface has been configured as a data communications equipment device.
The command encapsulation frame-relay ietf has been used on the Serial 0/0/0 interface.

21. What consideration must be taken into account if RIP is used on Frame Relay multiaccess networks?
To forward routing updates, address-to-DLCI mapping must be done via the use of the frame-relay map command coupled with the broadcast keyword.
Inverse ARP must be enabled to turn routing update broadcasts into unicast traffic that can be propagated to other Frame Relay nodes.
Because broadcast traffic is not supported, RIPv1 cannot be implemented on Frame Relay networks.
To forward broadcast routing updates, dynamic mapping must be enabled.

22.

Refer to the exhibit. You are a network administrator who has been tasked with completing the Frame Relay topology that interconnects two remote sites. Router HQ belongs to both the 172.16.1.0/24 and 172.16.2.0/24 subnets with IP addresses of 172.16.1.3 and 172.16.2.3 respectively. Traffic between R1 and R2 must travel through HQ first. How should the serial interface on HQ be configured to complete the topology?
one multipoint subinterface
two point-to-point subinterfaces
with the physical interface configured with two ip addresses
one IP address on a point-to-point subinterface and one IP address on the physical interface

CCNA 4 chapter 2

2012-01-13T21:47:00.001+07:00

1.Refer to the exhibit. Router R1, the DCE device, has just been configured for PPP encapsulation with authentication. What series of commands will allow another router, the DTE device, to communicate over its serial 0/0/0 interface to router R1?
Router(config)# hostname R3
R3(config)# username R1 password Cisco
R3(config)# interface Serial 0/0/0
R3(config-if)# encapsulation ppp
R3(config-if)# ip address 172.16.3.3 255.255.255.0
R3(config-if)# ppp authentication chap
Router(config)# hostname R3
R3(config)# username R3 password Cisco
R3(config)# interface Serial 0/0/0
R3(config-if)# encapsulation ppp
R3(config-if)# ip address 172.16.3.3 255.255.255.0
R3(config-if)# ppp authentication chap
Router (config)# username Router password Cisco
Router (config)# interface Serial 0/0/0
Router (config-if)# clockrate 64000
Router (config-if)# encapsulation ppp
Router (config-if)# ip address 172.16.3.1 255.255.255.0
Router config-if)# ppp authentication chap
Router (config)# username R1 password Cisco
Router config)# interface Serial 0/0/0
Router (config-if)# clockrate 64000
Router config-if)# encapsulation ppp
Router (config-if)# ip address 172.16.3.1 255.255.255.0
Router (config-if)# ppp authentication chap

2. Which serial communications DTE/DCE interface standard is used to provide high-speed connectivity of up to 52 Mbps between LANs and is found on many high-end Cisco routers?
EIA/TIA 232 (RS-232)
EIA/TIA 422 (RS-422)
EIA/TIA 423 (RS-423)
EIA/TIA-612/613 (HSSI)
ITU V.35

3. Which three statements are true regarding LCP? (Choose three.)
It is responsible for negotiating link establishment.
It negotiates options for Layer 3 protocols running over PPP.
It uses MD5 encryption while negotiating link establishment parameters.
It terminates the link upon user request or the expiration of an inactivity timer.
It can test the link to determine if link quality is sufficient to bring up the link.
It monitors the link for congestion and dynamically adjusts the acceptable window size.
4.

Refer to the exhibit. On the basis of the show interface Serial0/0 output, how many NCP sessions have been established?
one
two
three
four

5. Which two statements are true about time-division multiplexing (TDM)? (Choose two.)
TDM relies on Layer 3 protocols to operate.
Multiple channels can transmit over a single link.
Original data streams must be reconstructed at the destination.
TDM methods vary depending on the Layer 2 protocol that is used.
It allows information from multiple channels to be allocated bandwidth on multiple wires.

6. Which authentication protocol can be spoofed to allow playback attacks?
MD5
CHAP
PAP
NCP

7.

Refer to the exhibit. What can be concluded about the function of the Serial 0/0/0 interface on the router after the commands are entered?
All username and password information that is sent will be encrypted.
All authentication on the serial link will be accomplished using a two-way handshake.
The Predictor algorithm will be used to compress all packets that are sent and received on the serial link.
The serial link will be closed if the number of received packets at the destination node falls below 90 percent of the packets that are sent.

8. Which three statements are correct about HDLC encapsulation? (Choose three.)
HDLC does not support CDP.
HDLC and PPP are compatible.
HDLC supports PAP and CHAP authentication.
HDLC implementation in Cisco routers is proprietary.
HDLC is the default serial interface encapsulation on Cisco routers.
HDLC uses frame delimiters to mark the beginnings and ends of frames.

9. What function do Network Control Protocols provide for a PPP connection?
to supply error detection
to establish and terminate data links
to provide authentication capabilities to PPP
to manage network congestion and to allow quality testing of the link
to allow multiple Layer 3 protocols to operate over the same physical link

10. What advantage does PPP have over HDLC for serial communications?
It can communicate more efficiently with other Cisco devices
It is less complex to configure
It has less Layer 2 overhead
It supports authentication

11.

Refer to the exhibit. What statement is true regarding the output shown?
LCP is in the process of negotiating a link.
LCP and NCP are waiting for CHAP authentication to complete.
LCP negotiation has been successful, but NCP negotiation is in progress.
Data is able to flow across this link.

12.

Refer to the exhibit. What statement is true regarding the output shown?
NCP has successfully negotiated.
The PAP passwords did not match, so the routers are trying CHAP authentication.
One router has suggested PAP authentication, and the other has accepted authentication but suggested CHAP authentication.
One router can only use PAP authentication while the other router can only use CHAP, so the connection has been rejected.

13. Which three statements correctly describe PPP authentication? (Choose three.)
PAP sends passwords in clear text.
PAP uses a 3-way handshake to establish a link.
PAP provides protection from repeated trial-and-error attacks.
CHAP uses a 2-way handshake to establish a link.
CHAP uses a challenge/response that is based on the MD5 hash algorithm.
CHAP uses repeated challenges for verification.

14.

Refer to the exhibit. While troubleshooting a serial interface, a technician enters the command show interface serial 0/0/0 . If the interface is in DCE mode, what two problems are likely to cause the indicated problem? (Choose two.)
The remote CSU or DSU has failed.
The router is not sensing a CD signal.
A timing problem has occurred on the cable.
The line is not physically connected to the CSU/DSU.
The router configuration contains the shutdown interface configuration command.

15. Why are serial connections preferred over parallel connections for long transmission lengths?
Parallel connections do not support error checking.
Parallel connections are subject to excessive attenuation.
Parallel connections are subject to clock skew and to crosstalk between wires.
Parallel connections transmit over only two wires and therefore transmit data more slowly.

16.

Refer to the exhibit. Which two statements are true regarding the output shown? (Choose two.)
The router has agreed on IP parameters.
The router has negotiated LCP successfully.
The router is negotiating IP compression options.
The router is requesting an IP address from its peer.
The router has accepted IP but not the suggested IP options.

17. What does the demarcation point represent in data communication physical circuits?
DTE/DCE interface on the device connecting to the Internet
location of the firewall or router
physical point at which the public network ends and the private customer network begins
tag assigned to the physical block where a cross-connect occurs

18.

Refer to the exhibit. Which statement is true about PPP operation?
Layer 2 is down.
LCP, IPCP, and CDPCP negotiations are in progress.
Only the link-establishment phase completed successfully.
Both the link-establishment and network-layer phase completed successfully.

19. Which two options can LCP negotiate? (Choose two.)
link quality
authentication
dynamic flow control
compression and network layer address for IP
connection-oriented or connectionless communication methods

20. Which PPP configuration option can be used to establish load balancing over the interfaces of a router?
callback
multilink
compression
error detection

21.

Refer to the exhibit. Router R1 is not able to communicate with a neighbor router that is directly connected to serial 0/0/0. What is the reason for this?
Interface Serial0/0/0 resets very frequently.
PPP LQM has shutdown the serial interface.
The serial interface has no input or output queues available.
The serial interface is not configured for a Layer 2 protocol.
The interface has been administratively shutdown with the shutdown command.

CCNA 4 chapter 1

2012-01-13T21:45:00.001+07:00

1. Which statement is true about the differences between a WAN and a LAN?
WANs generally support higher bandwidth than LANs support.
A WAN link typically traverses shorter geographic distances than a LAN link traverses.
A WAN often relies on the services of carriers, such as telephone or cable companies, but a LAN does not.
All WAN implementations generally use the same Layer 2 protocol but there are many accepted LAN Layer 2 protocols in use.

2. A U.S. company requires a WAN connection used only to transfer sales data from individual stores to the home office. All transfers will occur after business hours. The required bandwidth for this connection is estimated to be less than 38 kbps. Which type of connection requires the least investment for this company?
ATM
ISDN
analog dialup
T1 Leased Line
3. What are two advantages of an analog PSTN WAN connection? (Choose two.)
low cost
availability
traffic encryption
available bandwidth
support for voice and video

4. Which WAN technology uses a fixed payload of 48 bytes and is transported across both switched and permanent virtual circuits?
ATM
ISDN
Frame Relay
metro Ethernet

5. Which three WAN devices can be found in the cloud? (Choose three.)
ATM switches
core routers
CSU/DSU
Ethernet switches
Frame Relay switches
repeaters

6. Which term describes a device that will put data on the local loop?
DLCI
DTE
DCE
BRI
PRI

7. What is an advantage of packet-switched technology over circuit-switched technology?
Packet-switched networks are less susceptible to jitter than circuit-switched networks are.
Packet-switched networks can efficiently use multiple routes inside a service provider network.
Packet-switched networks do not require an expensive permanent connection to each endpoint.
Packet-switched networks usually experience lower latency than circuit-switched networks experience.

8. Which statement is true about data connectivity between a customer and a service provider?
Normally the CSU/DSU is the designated demarcation point for the service provider but not the customer.
The segment between the demarcation point and the central office is known as the "last mile."
The local loop is the segment between the CSU/DSU and the serial port on a router.
Putting data on the local loop is the responsibility of the DTE.

9. A company needs a WAN connection that is capable of transferring voice, video, and data at a minimum data rate of 155 Mbps. Which WAN connection is the best choice?
X.25
DSL
ATM
ISDN BRI
ISDN PRI

10. Which statement is true of the functionality of the layers in the hierarchical network model?
The purpose of the access layer is to provide very high bandwidth communications between network devices.
Most security screening to prevent unauthorized entry to the network happens at the core layer.
Untrusted external connections are segmented from the rest of the network at all three levels.
The distribution layer aggregates WAN connections at the edge of the campus.

11. Why is the call setup time of a circuit-switched WAN implementation considered a drawback?
Routing protocols are incompatible with this function.
It restricts the communication sent to voice traffic only.
A telephone must be used to initially start transferring data.
Data cannot be transferred until a circuit has been established.

12. For digital lines, which device is used to establish the communications link between the customer equipment and the local loop?
CSU/DSU
Frame Relay switch
ISDN switch
modem
PBX switch

13. Which packet-switched WAN technology offers high-bandwidth connectivity capable of managing data, voice, and video all on the same infrastructure?
Time Division Multiplexing (TDM)
metro Ethernet
Integrated Services Digital Network (ISDN)
Public Switched Telephone Network (PSTN)

14. Which networking device is typically used to concentrate the dial-in and dial-out traffic of multiple users to and from a network?
core router
access server
Frame Relay switch
ATM switch

15. Which two devices are commonly used as data communications equipment? (Choose two.)
modem
router
CSU/DSU
ISDN switch
Ethernet switch

16. Which two features are identified with Frame Relay connections? (Choose two.)
53-byte cells
DLCI
DSLAM
PVC
SPID

17. Which statement about WAN protocols is correct?
ATM differs from other WAN protocols in that it uses variably sized packets.
Most WAN protocols use HDLC or a variant of HDLC as a framing mechanism.
The frame header consists of the frame check sequence and cyclic redundancy check.
ISDN differs from Frame Relay, HDLC, and ATM in that it is packet-switched rather than circuit-switched technology.

18. Which switching type will allow the communication devices in the provider network to be shared and only allocated to an individual subscriber during data transfer?
circuit-switched
dedicated switched lines
frame-switched
packet-switched

19. What can cause a reduction in available bandwidth on a cable broadband connection?
smaller cells
number of subscribers
committed information rate
distance from the central office of the provider

20. What three terms are associated with ISDN PRI? (Choose three.)
cell
DLCI
circuit switching
packet switching
data bearer channels
time-division multiplexing

21. At which two layers of the OSI model does a WAN operate? (Choose two.)
Physical Layer
Data Link Layer
Network Layer
Transport Layer
Presentation Layer
Application Layer

22. What type of connectivity is established when VPNs are used from the remote site to the private network?
PVCs
DLCIs
tunnels
dedicated Layer 2 links