Information Security

Cloud Computing Service Providers

2014-05-31T16:42:00.000+05:30

Amazon Web Services (AWS)
CloudBees
CloudSigma
Google Compute Engine
IBM cloud
Joyent
Microsoft Azure
OpenShift
Rackspace
Verizon Cloud Compute

mPOS (Mobile Point Of Sale)

2014-05-30T16:14:00.000+05:30

mPOS

Mpos (mobile point of sale) is the ability for a customer transaction to be documented by a smart phone or tablet instead of by a traditional checkout register or other point-of-sale terminal.

Small Business and Large Retailers are turning to mobile point-of-sale to increase sales and broaden their customer base.

List of mPOS companies in India

1. Aasaanpay

2. Ezetap

3. MobiSwipe

4. Mosambee

5. MRL Posnet

6. Mswipe

7. Paynear

Features :

1. Support magnetic stripe and EMV (chip) cards
2. Support PIN entry
3. Support electronic receipt Via SMS/email
4. Support on multiple mobile and tablet platforms – iOS, Android and Windows
5. Void or capture payments in real-time
6. Enables merchants to view their payment history

Internet Technologies - Founders

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01. GOOGLE : Larry Page & Sergey Brin

02. FACEBOOK : Mark Zuckerberg

03. YAHOO : David Filo & Jerry Yang

04. TWITTER : Jack Dorsey & Dick Costolo

05. INTERNET : Tim Berners Lee

06. LINKDIN : Reid Hoffman,Allen Blue & Koonstantin Guericke

07. EMAIL : Shiva Ayyadurai

08. GTALK : Richard Wahkan

09. WHATS UP : Laurel Kirtz

10. HOTMAIL : Sabeer Bhatia

11. ORKUT : Orkut Buyukkokten

12. WIKIPEDIA : Jimmy Wales

13. YOU TUBE : Steve Chen,Chad Hurley & Jawed Karim

14. REDIFFMAIL : Ajit Balakrishnan

15. NIMBUZZ : Martin Smink & Evert Jaap Lugt

16. MYSPACE : Chris Dewolfe & Tom Anderson

17. IBIBO : Ashish Kashyap

18. OLX : Alec Oxenford & Fabrice Grinda

19. SKYPE : Niklas Zennstrom,JanusFriis & Reid Hoffman

20. OPERA : Jon Stephenson von Tetzchner & Geir lvarsoy

21. MOZILLA FIREFOX : Dave Hyatt & Blake Ross

22. BLOGGER : Evan Willams.

2013-12-16T17:25:00.000+05:30

Top 10 Security Compliance & Regulations standards by Industry

PCI DSS
PA DSS
P2PE
ISO 27001
HIPAA
FISMA
DPA
FedRAMP
GLBA
FFIEC

Symmetric encryption Vs Asymmetric encryption

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What are encryption vulnerabilities?

Breaking symmetric encryption

There are two methods of breaking symmetric encryption - brute force and cryptanalysis.
Brute Force Attack is a form of attack in which each possibility is tried until success is obtained. Typically, a ciphertext is deciphered under different keys until plaintext is recognized. No encryption software that is entirely safe from the brute force method, but if the number of possible keys is high enough, it can make a program astronomically difficult to crack using brute force. But the more bits in a key, the more secure it is, so choose software with as many bits as possible.
Cryptanalysis is a form of attack that attacks the characteristics of the algorithm to deduce a specific plaintext or the key used.

Weak passwords

In every kind of encryption software, there is some kind of password that must be created so that the recipients of the information can read it. Creating a strong password that cannot be easily guessed is just as important as choosing a good algorithm or strong encryption software.

Remembering passwords

If you forget your password, you will not be able to decrypt data that you have encrypted. Be sure to make a backup copy of your password and store it in a safe place.

Secret keys exchanging and storing

Symmetric key algorithms require sharing the secret key - both the sender and the receiver need the same key to encrypt or decrypt data. Anyone who knows the secret key can decrypt the message. So it is essential that the sender and receiver have a way to exchange secret keys in a secure manner. The weakness of symmetric algorithms is that if the secret key is discovered, all messages can be decrypted. So, secret key need to be changed on a regular basis and kept secures during distribution and while using.

Asymmetric Encryption (Public Key Encryption)

Asymmetric encryption uses different keys for encryption and decryption. The decryption key is very hard to derive from the encryption key. The encryption key is public so that anyone can encrypt a message. However, the decryption key is private, so that only the receiver is able to decrypt the message. It is common to set up "key-pairs" within a network so that each user has a public and private key. The public key is made available to everyone so that they can send messages, but the private key is only made available to the person it belongs to.

How Asymmetric Encryption (Public Key Encryption) works:

The sender and the recipient must have the same software. The recipient makes a pair of keys - public key and private key (both keys can be unlocked with a single password). Public key can be used by anyone with the same software to encrypt a message. Public keys can be freely distributed without worrying since it is only used to scramble (encrypt) the data. The sender does not need the recipient's password to use his or her public key to encrypt data. The recipient's other key is a private key that only he or she can use when decrypting the message. Private Key should never be distributed since the private key assures that only the intended recipient can unscramble (decrypt) data intended for him or her.
To understand asymmetric encryption better please read an example:
For example, Jack makes public key A and private key A, and Jill makes public key B and private key B. Jack and Jill exchange their public keys. Once they have exchanged keys, Jack can send an encrypted message to Jill by using Jill's public key B to scramble the message. Jill uses her private key B to unscramble it. If Jill wants to send an encrypted message to Jack, she uses Jack's public key A to scramble her message, which Jack can then unscramble with his private key A. Asymmetric cryptography is typically slower to execute electronically than symmetric cryptography.

Some Asymmetric Algorithms (public key algorithms) such as RSA allow the process to work in the opposite direction as well: a message can be encrypted with a private key and decrypted with the corresponding public key. If the recipient wants to decrypt a message with Bob's public key he/she must know that the message has come from Bob because no one else has sender's private key. Digital signatures work this way.

Some examples of popular asymmetric encryption algorithms:
RSA
DSA
PGP

RSA encryption

RSA is the best known public key algorithm, named after its inventors: Rivest, Shamir and Adleman. RSA uses public and private keys that are functions of a pair of large prime numbers. Its security is based on the difficulty of factoring large integers. The RSA algorithm can be used for both public key encryption and digital signatures. The keys used for encryption and decryption in RSA algorithm, are generated using random data. The key used for encryption is a public key and the key used for decryption is a private key. Public keys are stored anywhere publicly accessible. The sender of message encrypts the data using public key, and the receiver decrypts it using his/her own private key. That way, no one else can intercept the data except receiver.

DSA

The Digital Signature Algorithm (DSA) is a United States Federal Government standard or FIPS for digital signatures. It was proposed by the National Institute of Standards and Technology (NIST) in August 1991 for use in their Digital Signature Standard (DSS).

PGP

PGP (Pretty Good Privacy) is a public-private key cryptography system which allows for users to more easily integrate the use of encryption in their daily tasks, such as electronic mail protection and authentication, and protecting files stored on a computer. PGP was originally designed by Phil Zimmerman. It uses IDEA, CAST or Triple DES for actual data encryption and RSA (with up to 2048-bit key) or DH/DSS (with 1024-bit signature key and 4096-bit encryption key) for key management and digital signatures. The RSA or DH public key is used to encrypt the IDEA secret key as part of the message.

Combination of Symmetric Encryption and Asymmetric Encryption

If we want the benefits of both types of encryption algorithms, the general idea is to create a random symmetric key to encrypt the data, and then encrypt that key asymmetrically. Once the key is asymmetrically encrypted, we add it to the encrypted message. The receiver gets the key, decrypts it with their private key, and uses it to decrypt the message.

How strong is protection in Encryption and Decryption?

Encryption and Decryption uses AES 256-bit key encryption algorithm. AES provides strong encryption and was selected by NIST as a Federal Information Processing Standard in November 2001 (FIPS-197). Currently, there are no computers that could break the encryption key in a reasonable amount of time (it will take millions of years). A password, or more precisely its hash (SHA 256), is used to protect the encryption key. Neither the password nor its hash is stored anywhere. If the password is not correct, it will be impossible to get the encryption key and consequently to decrypt information

Encryption

2012-06-18T21:11:00.001+05:30

What is encryption?

Encryption is the conversion of data into a form, called a cipher text. There are two basic techniques for encrypting information: symmetric encryption (also called secret key encryption) and asymmetric encryption (also called public key encryption).

How encryption works

Encryption program uses an encryption algorithm (complex mathematical processes) to encrypt and decrypt the data. Encryption algorithm creates specific strings of data used for encryption - keys that consist of long strings of bits or binary numbers. The more bits in the key, the more the number of possible combinations of binary numbers that makes the code more difficult to break. Then encryption algorithm scrambles data by combining the bits in the key with the data bits. In symmetric encryption, the same key is used to scramble (encrypt) and unscramble (decrypt) data. In asymmetric key encryption, two different keys are required - one for encryption and one for decryption.

Why you need encryption

Nowadays when more and more sensitive information is stored on computers and transmitted over the Internet, we need to ensure information security and safety.

One of the most common uses of encryption is encrypting emails. Sending sensitive messages, documents and files over the Internet is like sending a postcard as all emails are transmitted in an unsecured form. It doesn't depend on if you send emails via public and private networks. Your message is totally open to interception by anyone along the way - so anybody - your ISP, your boss, etc. can read your emails. Even if you connect to your server and send your emails via SSL, it only means that your emails can't be seen while transmitting between you and your server. When your email reaches your server, it can be seen by your email service provider. Then your server usually sends your email to the recipient in an unsecured way and your email can also be easily seen by anyone.

Private network, where email goes directly to a mail server and resides there until it is retrieved, also doesn't provide necessary security level, as you email can be seen e.g. by network administrator, your boss, etc.

Of course, you may believe that your personal email does not contain any private information, but everyone has got something to keep in secret from his family, neighbours or colleagues. It could be financial, sexual, social, political, or professional secrets. There is really only one sure way to protect your email privacy - using encryption.

Symmetric Encryption

Symmetric Encryption (also known as symmetric-key encryption, single-key encryption, one-key encryption and private key encryption) is a type of encryption where the same secret key is used to encrypt and decrypt information or there is a simple transform between the two keys.
A secret key can be a number, a word, or just a string of random letters. Secret key is applied to the information to change the content in a particular way. This might be as simple as shifting each letter by a number of places in the alphabet. Symmetric algorithms require that both the sender and the receiver know the secret key, so they can encrypt and decrypt all information.
There are two types of symmetric algorithms: Stream algorithms (Stream ciphers) and Block algorithms (Block ciphers).

Types of Symmetric algorithms (Symmetric-key algorithms)

Symmetric algorithms (Symmetric-key algorithms) use the same key for encryption and decryption. Symmetric-key algorithms can be divided into Stream algorithms (Stream ciphers) and Block algorithms (Block ciphers).

Stream Ciphers
Stream ciphers encrypt the bits of information one at a time - operate on 1 bit (or sometimes 1 byte) of data at a time (encrypt data bit-by-bit). Stream ciphers are faster and smaller to implement than block ciphers, however, they have an important security gap. If the same key stream is used, certain types of attacks may cause the information to be revealed.

Block Ciphers

Block cipher (method for encrypting data in blocks) is a symmetric cipher which encrypts information by breaking it down into blocks and encrypting data in each block. A block cipher encrypts data in fixed sized blocks (commonly of 64 bits). The most used block ciphers are Triple DES and AES.

Some examples of symmetric encryption algorithms:

AES/Rijndael
Blowfish
CAST5
DES
IDEA
RC2
RC4
RC6
Serpent
Triple DES
Two fish

AES/Rijndael encryption

AES stands for Advanced Encryption Standard. AES is a symmetric key encryption technique which replaces the commonly used Data Encryption Standard (DES).
It was the result of a worldwide call for submissions of encryption algorithms issued by the US Government's National Institute of Standards and Technology (NIST) in 1997 and completed in 2000.
The winning algorithm, Rijndael, was developed by two Belgian cryptologists, Vincent Rijmen and Joan Daemen. AES provides strong encryption and was selected by NIST as a Federal Information Processing Standard in November 2001 (FIPS-197).
The AES algorithm uses three key sizes: a 128-, 192-, or 256-bit encryption key. Each encryption key size causes the algorithm to behave slightly differently, so the increasing key sizes not only offer a larger number of bits with which you can scramble the data, but also increase the complexity of the cipher algorithm.

Blowfish

Blowfish is a symmetric encryption algorithm (64-bit cipher) designed in 1993 by Bruce Schneier as an alternative to existing encryption algorithms. Blowfish has a variable key length - from 32 bits to 448 bits. Since then Blowfish has been analyzed considerably, and is gaining acceptance as a strong encryption algorithm.

CAST

CAST stands for Carlisle Adams and Stafford Tavares, the inventors of CAST. CAST is a popular 64-bit block cipher allowing key sizes up to 128 bits.

Data Encryption Standard (DES)

Data Encryption Standard (DES) is a block cipher with 64-bit block size that uses 56-bit keys. DES was invented over 20 years ago by IBM in response to a public request from the National Bureau of Standards. Due to recent advances in computer technology, some experts no longer consider DES secure against all attacks; since then Triple-DES (3DES) has emerged as a stronger method. Using standard DES encryption, Triple-DES encrypts data three times and uses a different key for at least one of the three passes giving it a cumulative key size of 112-168 bits.

IDEA

IDEA stands for International Data Encryption Algorithm. IDEA is a symmetric encryption algorithm that was developed by Dr. X. Lai and Prof. J. Massey to replace the DES standard. Unlike DES though it uses a 128 bit key. This key length makes it impossible to break by simply trying every key.

RC2

RC2 is a variable-key-length cipher. It was invented by Ron Rivest for RSA Data Security, Inc. Its details have not been published.

RC4

RC4 was developed by Ron Rivest in 1987. It is a variable-key-size stream cipher. It is a cipher with a key size of up to 2048 bits (256 bytes).

RC6

RC6 is a symmetric key block cipher derived from RC5. It was designed by Ron Rivest, Matt Robshaw, Ray Sidney, and Yiqun Lisa Yin to meet the requirements of the Advanced Encryption Standard (AES) competition. RC6 encryption algorithm was selected among the other finalists to become the new federal Advanced Encryption Standard (AES).

Serpent

Serpent is a block cipher developed by Ross Anderson, Eli Biham and Lars Knudsen. Serpent can work with different combinations of key lengths. Serpent was also selected among other five finalists to become the new federal Advanced Encryption Standard (AES).

Triple DES

Triple DES is a variation of Data Encryption Standard (DES). It uses a 64-bit key consisting of 56 effective key bits and 8 parity bits. The size of the block for Triple-DES is 8 bytes. Triple-DES encrypts the data in 8-byte chunks. The idea behind Triple DES is to improve the security of DES by applying DES encryption three times using three different keys.

Twofish

Twofish is a symmetric block cipher. Twofish has a block size of 128 bits and accepts keys of any length up to 256 bits.
Twofish encryption algorithm was designed by Bruce Schneier, John Kelsey, Chris Hall, Niels Ferguson, David Wagner and Doug Whiting. The National Institute of Standards and Technology (NIST) investigated Twofish as one of the candidates for the replacement of the DES encryption algorithm.

How SSL Works

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SSL is a protocol that provides privacy and integrity between two communicating applications using TCP/IP. The Hypertext Transfer Protocol (HTTP) for the World Wide Web uses SSL for secure communications.

The data going back and forth between client and server is encrypted using a symmetric algorithm such as DES or RC4. A public-key algorithm-usually RSA-is used for the exchange of the encryption keys and for digital signatures. The algorithm uses the public key in the server's digital certificate. With the server's digital certificate, the client can also verify the server's identity. Versions 1 and 2 of the SSL protocol provide only server authentication. Version 3 adds client authentication, using both client and server digital certificates.

The SSL Handshake

An SSL connection is always initiated by the client. At the beginning of an SSL session, an SSL handshake is performed. This handshake produces the cryptographic parameters of the session.

The client sends a client "hello" message that lists the cryptographic capabilities of the client (sorted in client preference order), such as the version of SSL, the cipher suites supported by the client, and the data compression methods supported by the client. The message also contains a 28-byte random number.
The server responds with a server "hello" message that contains the cryptographic method (cipher suite) and the data compression method selected by the server, the session ID, and another random number.

Note:

The client and the server must support at least one common cipher suite, or else the handshake fails. The server generally chooses the strongest common cipher suite.

The server sends its digital certificate. (The server uses X.509 V3 digital certificates with SSL.)

If the server uses SSL V3, and if the server application (for example, the Web server) requires a digital certificate for client authentication, the server sends a "digital certificate request" message. In the "digital certificate request" message, the server sends a list of the types of digital certificates supported and the distinguished names of acceptable certificate authorities.

The server sends a server "hello done" message and waits for a client response.
Upon receipt of the server "hello done" message, the client (the Web browser) verifies the validity of the server's digital certificate and checks that the server's "hello" parameters are acceptable.

If the server requested a client digital certificate, the client sends a digital certificate, or if no suitable digital certificate is available, the client sends a "no digital certificate" alert. This alert is only a warning, but the server application can fail the session if client authentication is mandatory.

The client sends a "client key exchange" message. This message contains the pre-master secret, a 46-byte random number used in the generation of the symmetric encryption keys and the message authentication code (MAC) keys, encrypted with the public key of the server.

If the client sent a digital certificate to the server, the client sends a "digital certificate verify" message signed with the client's private key. By verifying the signature of this message, the server can explicitly verify the ownership of the client digital certificate.

Note:

An additional process to verify the server digital certificate is not necessary. If the server does not have the private key that belongs to the digital certificate, it cannot decrypt the pre-master secret and create the correct keys for the symmetric encryption algorithm, and the handshake fails.

The client uses a series of cryptographic operations to convert the pre-master secret into a master secret, from which all key material required for encryption and message authentication is derived. Then the client sends a "change cipher spec" message to make the server switch to the newly negotiated cipher suite. The next message sent by the client (the "finished" message) is the first message encrypted with this cipher method and keys.
The server responds with a "change cipher spec" and a "finished" message of its own.
The SSL handshake ends, and encrypted application data can be sent.

Difference Between RIPv1 and RIPv2

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RIP v1	RIP v2
Distance-Vector	Distance-Vector
Maximum hop count = 15	Maximum hop count = 15
Classful	Classless
Broadcast based	Use Multicast 224.0.0.9
No support for VLSM	Support VLSM
No authentication	Allows MD5 authentication
No support for discontinuous networks	Support discontinuous network

RIP v2

2011-11-19T21:00:00.001+05:30

RIPv2 is a classless, distance vector routing protocol as defined in RFC 1723. Because RIPv2 is a classless routing protocol, which means, it includes the subnet mask with the network addresses in the routing updates. As with other classless routing protocols, RIPv2 supports CIDR supernets, VLSM and discontiguous networks.

Due to the deficiencies of RIPv1, RIP version 2 (RIPv2) was developed sometime in 1993. It’s equipped with the ability to support subnet information and supports Classless Inter-Domain Routing (CIDR). A router that receives routing updates from multiple routers advertising the same classful summary route cannot determine which subnets belong to which summary route. This inability leads to unexpected results including misrouted packets.

However, with RIPv2 automatic summarization can be disabled with the no auto-summary command. Automatic summarization must be disabled to support discontiguous networks.

RIPv2 still maintains the hop count limit of 15 and incorporated a password authentication mechanism. However, passwords were transmitted in clear-text format, which were found insufficient for secure communications on the Internet.

The default version of RIP is version 1. The command version 2 is used to modify RIPv1 to RIPv2.

Use The show ip protocols command to view that RIP is now sending and receiving version 2 updates and whether or not automatic summarization is in effect.

RIPv2 is actually an enhancement of RIPv1's features and extensions rather than an entirely new protocol. Some of these enhanced features include:

•Next-hop addresses included in the routing updates

•Use of multicast addresses in sending updates

•Authentication option available

Like RIPv1, RIPv2 is a distance vector routing protocol. Both versions of RIP share the following features and limitations:

•Use of holddown and other timers to help prevent routing loops.

•Use of split horizon or split horizon with poison reverse to also help prevent routing loops.

•Use of triggered updates when there is a change in the topology for faster convergence.

•Maximum hop count limit of 15 hops, with the hop count of 16 signifying an unreachable network.

SSL Vendor List

2011-08-27T12:30:00.003+05:30

1. Verisign

2. Thawte

3. Geotrust

4. GoDaddy

5. Comodo

6. Entrust

7. Digicert

8. Globalsign

What is Smurf attack & How to prevent it ?

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Smurf attack is the form of generating uncontrolled amount of traffic in victims network.

The process of smurf attack is as follows:

1. Send huge amount of ICMP request to the broadcast address of the victim network(Directed Broadcast Address).

2. Source IP of the attacker must be spoofed.

3. The ICMP request reach the gateway of the victim network.

4. Each host on the victim network will respond to the ICMP request (Amplifying the ping requests)

5. It creates uncontrollable amount of traffic from victim's network.

6. It will consume the useful bandwidth and the server will be down in few minutes.

How to prevent smurf attack ?

1. Configure individual hosts and routers not to respond to ping requests or broadcasts.

2. Configure routers not to forward packets directed to broadcast addresses.

Denial of Service (DOS) attacks

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Denial of Service (DOS) attacks are intended to shut down the servers for a period of time. To make site nonfunctional for a time the main part of attack is DOS attack. DOS attacks are usually doing by following methods:

1. Send unlimited amount of packets to the server.

2. Executing malwares

3. Teardrop attack

4. Application level flood

Sending unlimited packets by ping command is also known as ICMP flood. This method can be done in the following way.

A simple DOS attack code would be:

ping {ip} -t -l 20000

On command prompt window you can type the following command. This command sends 20000 bytes of data to the ip, in a single packet. The -t is to ping the specified host until stopped and -l is to specify the buffer size. A Teardrop attack involves sending mangled Internet Packet fragments with overlapping, over-sized, payloads to the target machine. In peer to peer attack thousands of computers will try to access a single computer at the same time. It will break down all the connection from the server at last the target machine will fail. Application level flood is by the mis-programming of an application installed on the server.So it will consume a major portion of server computing power and memory.

DOS attack with ping flood will work only if the following cafeterias are satisfied:

1. Attacker should have higher bandwidth than the victim.

2. Victim should respond to the ping requests

IPV4 vs IPV6

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Address Space
IPv4:4 Billion Addresses
IPv6:2^128
79 Octillion times the IPv4 address space

Configuration
IPv4: Manual or use DHCP
IPv6: Universal Plug and Play (UPnP) with or without DHCP
Lower Operation Expenses and reduce error

Broadcast / Multicast
IPv4: Uses both
IPv6: No broadcast and has different forms of multicast
Better bandwidth efficiency

Anycast support
IPv4: Not part of the original protocol
IPv6: Explicit support of anycast
Allows new applications in mobility, data center

Network Configuration
IPv4: Mostly manual and labor intensive
IPv6: Facilitate the re-numbering of hosts and routers
Lower operation expenses and facilitate migration

QoS support
IPv4: ToS using DIFFServ
IPv6: Flow classes and flow labels
More Granular control of QoS

Security
IPv4: Uses IPsec for Data packet protection
IPv6: IPsec becomes the key technology to protect data and control packets
Unified framework for security and more secure computing environment

Mobility
IPv4: Uses Mobile IPv4
IPv6: Mobile IPv6 provides fast handover, better router optimization and hierarchical mobility
Better efficiency and scalability; Work with latest 3G mobile technologies and beyond.

Google Over IPV6

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At Google, we believe that IPv6 is essential to the continued health and openness of the Internet – and that by allowing all devices on a network to talk to each other directly, IPv6 will enable innovation and allow the Internet's continued growth. Typical Google users do not need to do anything to prepare for IPv6, but we are working with network operators to support the transition.

In March 2008, we began offering Google search over IPv6 on IPv6-only websites like ipv6.google.com (IPv6 connection required), but other Google products were not generally available over IPv6.

That's why we created Google over IPv6. If you operate a network that supports IPv6, we may be able to enable Google over IPv6, letting you give users seamless access to most Google services over IPv6 simply by going to the same websites they usually use, such as www.google.com.

How it works

Google over IPv6 uses the IPv4 address of your DNS resolver to determine whether a network is IPv6-capable. If you enable Google over IPv6 for your resolver, IPv6 users of that resolver will receive AAAA records for IPv6-enabled Google services.

Normally, if a DNS resolver requests an IPv6 address for a Google web site,
it will not receive one…

…but a DNS resolver with Google over IPv6 will receive an IPv6 address,
and its users will be able to connect to Google web sites using IPv6.

How to get started using Google over IPv6

To qualify for Google over IPv6, your network must meet a number of requirements. These include:

Low latency, redundant paths to Google using direct peering or reliable transit
Production-quality IPv6 support and reliability
Separate DNS servers for your IPv6 users (not shared with IPv4-only users)
Users who have opted in to IPv6 services and know how to opt out if they experience problems with Google services

Know about IPV6 ?

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IPv6 or IP version 6 is the next generation Internet protocol which will eventually replace the current protocol IPv4. IPv6 has a number of improvements and simplifications when compared to IPv4. The primary difference is that IPv6 uses 128 bit addresses as compared to the 32 bit addresses used with IPv4. This means that there are more available IP addresses using IPv6 than are available with IPv4 alone. For a very clear comparison, in IPv4 there is a total of 4,294,967,296 IP addresses. With IPv6, there is a total of 18,446,744,073,709,551,616 IP addresses in a single /64 allocation.

To also help illustrate the sheer magnitude of available IP addresses using IPv6, you can get 65536 /64 allocations out of a single /48, and then 65536 /48 allocations out of a single /32. Many Service Providers are getting /32 allocations from their Regional Internet Registry (RIR) like ARIN, APNIC, RIPE, etc.

A significant difference between IPv6 and IPv4 is the address notation. IPv4 uses a period (.) between each octet, compared to IPv6 which uses a colon (:). With IPv6, if you have a series of zeroes in a row, the address need not be written out completely. You can use a double colon (::) to represent that series of zeroes, however you can only use that once. For example, if you have an address like "2001:0DB8:0000:0003:0000:01FF:0000:002E", it can be written like "2001:DB8::3:0:1FF:0:2E" or "2001:DB8:0:3:0:1FF::2E", but would never be written like "2001:DB8::3::1ff::2E". You also cannot have three colons in a row (:::).

IPv6 availability depends on your Service Provider, either at home or for work. In a dual-stack environment, IPv4 and IPv6 co-exist along the same connection and don't require any special kind of connection. If dual-stack is not available, you might find yourself using an IP tunneling product or service to bring IPv6 connectivity to you. IPv4 exhaustion, as of this writing, is estimated to happen sometime in early or mid 2011. When this happens, IPv4 won't simply disappear off the face of the Internet, but continued explosive growth requiring more unique IP address assignments will mean using more and more of the abundant IPv6 address space.

Many Operating System platforms have native IPv6 support these days. The UNIX based platforms like Linux, BSD (Free, Open, Net) & MacOSX have had IPv6 support enabled for years now. Microsoft Windows starting having native IPv6 support enabled by default with it's Vista and Windows 2008 products. Earlier Windows versions like 2000/2003/XP had to have it installed optionally, and did not have as robust features that are available in the newer versions of Windows. Even common web browsing and email software will use IPv6 if it is enabled and available, without having to check off an option or special configuration. The transition from IPv4 to IPv6 is being worked on to be as seamless as possible, and many might not even notice the subtle changes in the coming years.

Prepare for IPV6

2011-04-07T17:27:00.000+05:30

Difference between RIP V1 & RIP V2

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Difference between RIP V1 & RIP V2.

RIP V1 : Distance Vector Maximum Hop count of 15 Classful No Support for VLSM No support for Discontigious networks.

RIP V2 : Distance Vector Maximum Hop count of 15 Classless Supports VLSM networks Supports Discontigious networks

Mulitcasting :

Any Communication between a single sender and multiple receivers.

In Networking Multicast messages are sent to a defined subset of the network addresses.

What is classful and classless routing ?

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Classful routing : Routing Protocol that do not send subnet mask information when a route update is sent out. All devices in the network must use the same subnet mask.

Eg : RIP V1

Classless routing : Routing that sends subnet mask information in the routing updates. Classless routing allows VLSM (Variable Length Subnet Masking)

Eg : RIP V2 EIGRP & OSPF.

what is the difference Between BRI & PRI ?

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Both BRI (Basic Rate Interface) and PRI (Primary Rate Interface) provide multiple digital bearer channels over which temporary connections can be made and data can be sent.

Features:

ISDN BRI services 2 B channels (64 kbps) and one D channel (16 kbps). The total bandwidth is 144 kbps.

In North America ISDN PRI service is PRI T1 total bandwidth 1.544 Mbps ( 23 B channel with 64 kbps + 1 D channel with 64 Kbps)

In Europe ISDN PRI service is PRI E1 total bandwidth 2.048 Mbps (30 B channel with 64 kbps + 1 D channel with 64 Kbps)

IPv6 Transition Technology

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IPv4 Vs IPv6

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PUBLIC DNS SERVER

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=> Service provider: Google
Google public dns server IP address:

8.8.8.8
8.8.4.4

=> Service provider: Dnsadvantage
Dnsadvantage free dns server list:

156.154.70.1
156.154.71.1

=> Service provider: OpenDNS
OpenDNS free dns server list / IP address:

208.67.222.222
208.67.220.220

=> Service provider: Norton
Norton free dns server list / IP address:

198.153.192.1
198.153.194.1

=> Service provider: GTEI DNS (now Verizon)
Public Name server IP address:

4.2.2.1
4.2.2.2
4.2.2.3
4.2.2.4
4.2.2.5
4.2.2.6

=> Service provider: ScrubIt
Public dns server address:

67.138.54.100
207.225.209.66

IPv6 Header

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IPv6 Header:

IPv6 header contains the following things:

Version - This field contains the version of the IP used in the packet. It is of 4-bit in IP version 6.
Traffic class - This is an 8-bits field determining the packet priority. Priority values subdivide into ranges: traffic where the source provides congestion control and non-congestion control traffic.
Flow label - This 20 bits specifies the QoS management. Originally created for giving real-time applications special service, but currently unused.
Payload length - This 16 bits determines the payload length in bytes. When cleared to zero, the option is a "Jumbo payload" (hop-by-hop).
Next header - This 8-bits field specifies the next encapsulated protocol. The values are compatible with those specified for the IPv4 protocol field.
Hop limit - This is an 8-bits field newly introduced in IPv6. It replaces the time to live field of IPv4.
Source Address - This 128 bits field determines the logical address of the host that is sending the packet.
Destination Address - This 128 bits field determines the logical address of the host that is receiving the packet.

Difference Between IPv4 and IPv6

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IPv4

Source and destination addresses are 32 bits (4 bytes) in length.
IPSec support is optional.
IPv4 header does not identify packet flow for QoS handling by routers.
Both routers and the sending host fragment packets.
Header includes a checksum.
Header includes options.
Address Resolution Protocol (ARP) uses broadcast ARP Request frames to resolve an IP address to a link-layer address.
Internet Group Management Protocol (IGMP) manages membership in local subnet groups.
ICMP Router Discovery is used to determine the IPv4 address of the best default gateway, and it is optional.
Broadcast addresses are used to send traffic to all nodes on a subnet.
Must be configured either manually or through DHCP.
Uses host address (A) resource records in Domain Name System (DNS) to map host names to IPv4 addresses.
Uses pointer (PTR) resource records in the IN-ADDR.ARPA DNS domain to map IPv4 addresses to host names.
Must support a 576-byte packet size (possibly fragmented).

IPv6

Source and destination addresses are 128 bits (16 bytes) in length.
IPSec support is required.
IPv6 header contains Flow Label field, which identifies packet flow for QoS handling by router.
Only the sending host fragments packets; routers do not.
Header does not include a checksum.
All optional data is moved to IPv6 extension headers.
Multicast Neighbor Solicitation messages resolve IP addresses to link-layer addresses.
Multicast Listener Discovery (MLD) messages manage membership in local subnet groups.
ICMPv6 Router Solicitation and Router Advertisement messages are used to determine the IP address of the best default gateway, and they are required.
IPv6 uses a link-local scope all-nodes multicast address.
Does not require manual configuration or DHCP.
Uses host address (AAAA) resource records in DNS to map host names to IPv6 addresses.
Uses pointer (PTR) resource records in the IP6.ARPA DNS domain to map IPv6 addresses to host names.
Must support a 1280-byte packet size (without fragmentation).

About IPV6

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