CGMP will be enabled on both the multicast router and the switch, but the router’s going to do all the work. The router will be sending Join and Leave messages to the switch as needed. PIM must be running on the router interface facing the switch before enabling CGMP, as you can see:

R1(config)#int e0

R1(config-if)#ip cgmp

WARNING: CGMP requires PIM enabled on interface

R1(config-if)#ip pim sparse

R1(config-if)#ip cgmp

When CGMP is first enabled on both the multicast router and switch, the router will send a CGMP Join message, informing the switch that a multicast router is now connected to it. This particular CGMP Join will contain a Group Destination Address (GDA) of 0000.0000.0000 and the MAC address of the sending interface. The GDA is used to identify the multicast group, so when this is set to all zeroes, the switch knows this is an introductory CGMP Join, letting the switch know that the multicast router is online.

The switch makes an entry in its MAC table that this router can be found off the port that the CGMP Join came in on. The router will send a CGMP Join to the switch every minute to serve as a keepalive.

A workstation connected to the switch on port 0/5 now wishes to join multicast group 225.1.1.1. The Join message is sent to the multicast router, but first it will pass through the switch. The switch will do what you’d expect it to do – read the source MAC address and make an entry for it in the MAC address table as being off port fast 0/5 if there’s not an entry already there. (Don’t forget that the MAC address table is also referred to as the CAM table or the bridging table.)

The router will then receive the Join request, and send a CGMP Join back to the switch. This CGMP Join will contain both the multicast group’s MAC address and the requesting host’s MAC address. Now the switch knows about the multicast group 225.1.1.1 and that a member of that group is found off port fast 0/5. In the future, when the switch receives frames destined for that multicast group, the switch will not flood the frame as it would an unknown multicast. Instead, the switch will forward a copy of the frame to each port that it knows leads to a member of the multicast group.

Two major benefits of CGMP are the explicit Join and Leave Group messages. In the next part of this BCMSN exam tutorial, we’ll take a look at the Leave Group messages.

Cisco CCNP / BCMSN Exam Tutorial: Configuring CGMP On Routers & Switches is a post from: Provins Sirock Technology Site

As you may have guessed, I like my gadgets and was fairly excited about the prospect of getting a new phone, especially with the incredible host of features now available on the latest phones. After much research, I settled on the Sony Ericsson K750i with its colour screen, digital camera (with panoramic feature), video capture, bluetooth connectivity, access to the internet, MP3 Player and FM Radio. It also allows use of a separate memory card up to 1Gb so I can store loads of photos, songs and video. It made phone calls too!

After receiving the phone I started to look into the daunting prospect of learning how to use the thing. The first task I had to tackle was getting all my phone numbers onto the phone. After consulting the manual, I found that it was possible to copy my address book directly from Microsoft Outlook on my computer over to the phone, saving me from having to manually key in all of my phone numbers. This would save me a lot of time, as long as I could get it to work!

All I needed to do was install the phone’s software onto my computer from the supplied CD-ROM and connect the phone to my computer using the supplied data cable. I also had the option of connecting my phone to my computer wirelessly using the Bluetooth facility to connect to my computer, this sounded very interesting, but meant I would have to get a USB Bluetooth Dongle for my computer, so I decided to leave that for later.

As these things have a habit of not working first time round, I thought I would follow the instructions to the word, rather than just delving in as I normally do! To my surprise, after following the steps in the Quick Set-up Guide, it actually worked! it was really that easy, my phone was connected to my computer and it worked. I made a few setting changes (as mentioned in the instructions) on the mobile phone software and within moments I had transferred all of my telephone numbers and addresses into my phone! The great thing here is that now I can update any new person and telephone number to my phone and my computer at the same time, all I need to do is connect the phone to the computer and one button automatically updates my computer with information on my phone or vice versa.

I then got even more adventurous and thought I would try and get some music onto the phone. I have never used MP3′s before, but heard loads about it and following the instructions, within 5 minutes I had music on my phone! It even sound good. Using the camera is great too, easy and useful at times, not having to carry a separate digital camera for snaps.

I thing that amazed me was how straightforward everything was, I had avoided changing the phone mainly because I did not fancy the hassle, but it was actually easier to set up then my old phone which was so basic in comparison. Within an hour I had charged the battery, added my lengthy contacts list and appointments onto the phone’s calendar as well as recorded a few songs. Brilliant!

Now all I need to do is expand the memory capacity of the phone as the few songs I have put onto the phone have already used most of the memory that comes free with the phone. Apparently, I just need to buy a Memory Stick and slot it into the phone then enjoy, will try it soon.

Iggy’s New Toy is a post from: Provins Sirock Technology Site

An antispyware and adware removal tool is essential for every computer, more so on the ones kids use. When children browse, Spyware preys on the surfing behavior of children, especially teens. When they download various programs these Trojans come bundled in it. A good example of this is the peer-to-peer music sharing programs, free games online, free screen savers and several song lyric sites that kids frequent. But if you educate your kids about spyware, and use antispyware software, you can fight spyware effectively.

The Things Spyware Does

Spyware can just invade your system and hijack your web browser. The sites that kids usually visit site trigger off endless popup windows on Internet Explorer and that’s when you know you’ve been hit. This results in the slowing down or crashing of your pc. When your pc is infested with adware, it turns unstable and behaves strangely. Some forms of spyware called key loggers or dialers can automatically make expensive long distance calls or track everything you do by logging your keystrokes. This steals private information and passwords, not to mention credit card information.

Spyware Prefers Teenagers

More than the little kids, it’s the teenagers that attract spyware more because of their browsing habits. Most of the sites they browse are full of free stuff. You pay the price with spyware. The peer-to-peer sharing network is the worst because these sites do not have any kind of antispyware policy and are fair game for spyware vendors. Teenagers are attracted by the freebies offered especially on sites that have to do with celebrities and entertainment. Added to these are the downloadable games, free emoticons and other stuff.

You must advise your kids that it is dangerous to download any thing from unknown sites. Tell them to beware of pop up windows that promise to clean up or scan your pc. They must know about companies that claim to sell antispyware but actually just lodge spyware into your system. Therefore it is necessary that you purchase antispyware software from a reliable company.

No Such Thing As A Free Download

The irony of the issue is that the spyware that proliferates in your pc is there because you agreed to it, without knowing you did. Kids get excited about getting free stuff, little knowing that they are consenting to install spyware and adware. Spyware is difficult to identify and by the time you realize it, it is too late. The best thing to do is to build awareness among your kids and encourage safe browsing and downloading patterns. Ensure that antispyware and adware removal tools protect your pc always.

Alert Your Kids To Spyware is a post from: Provins Sirock Technology Site

MICROSOFT TO THE RESCUE – Put into your calendar the 2nd Tuesday of each month. That is the normal day on which Microsoft releases to the world whatever critical patches it determines that we need. (Of course, on occasion, Microsoft releases patches on other days – particularly if the problem to be fixed is deemed to be sufficiently troublesome.

IT’S AVAILABLE, SO NOW WHAT – Basically, you want to get the patches installed on your PC. “Not so fast,” you may say – particularly if you are the one responsible for other PCs. You will want some assurance that the patches which are intended to protect your PC will not cause some program to malfunction. You may wish to install the patches on a test PC before you unleash them to your public. For most of you, however, the time it takes to perform such tests is not worth the added risk to which you put your PC while you wait to complete the tests. My advice is to install the patches and take the extra protection from potential shutdowns, total malfunctions, and possible loss of privacy for the risk that an application program may temporarily stop working.

SIMPLE IS GOOD – From within the Internet Explorer under Tools/Windows Update, you can choose to have critical patches from Microsoft automatically downloaded and installed at a time and day of the week of your choice. You can also choose to check daily at a particular time. You may choose to select Tuesday (or Wednesday in case you wanted Tuesday but were not sure of the time of day that the patches might be available). That should work for most patches because they will come on a Tuesday and will be available at any time on Wednesday. I prefer to check every day. If there are no patches, the test is fast. If there are patches, I get them that much sooner. That is simple and adds, I believe, the greatest level of operating system safety and stability.

YOU CHOOSE – You may do the patches automatically every day or one day per week. You may do the patches manually. Just choose to do the patches as soon as possible and practical.

This article contains suggestions for the use of utility programs under the Windows operating system. They are based on years of use, but they may not be the right suggestions for you and your PC environment. Before you follow any technical suggestion, be sure that you have a current (and tested) backup of all system and data files and that you can restore the system if necessary. You are welcome to contact me if you encounter a problem, but I assume no responsibility for your actions and/or use of the information provided and disclaim any legal responsibility for any negative results of such actions.

Copyright 2006 by Tim Flynt. All rights reserved.

Tim Flynt has spent over 25 years dedicated to efficient application and utility systems. Experienced in higher education, entertainment, and software development organizations. Current interest in “PC Maintenance Management.”

http://AcceleratedOffice.com

Condoms for Your PC – Microsoft Patches! is a post from: Provins Sirock Technology Site

Used computers are bought by either students who do not have good savings or earnings or they are bought by educational institutions like the schools and universities. Some parents buy used computers for their children just for browsing the Internet and to play games. For this purpose, a used computer is more than sufficient than spending huge amounts on a new computer. These target segments however require used computers in a good working condition as well as for a lesser price. Most of the used computers are sold in the online market, as it attracts all sorts of buyers. There are many numbers of online classifieds or auctions or online dealers who sell used computers. Selling used computers are a better option than throwing them as trash or keeping them in a corner occupying space and collecting dust.

The first and important step is to improve the appearance of the used computer by wiping it clean free of dust and dirt. Any buyer would get impressed by the way the computer looks, looks make the first impression. The selling price of a clean used computer is always better than the one, which is full of dirt and dust.

All the software manual, operating system and other supporting discs that came with the computer should be in tact. This will add more value, when selling the used computer and also will make the buyer consider the person who is selling the used computer as a trusted seller.

The most important thing to do before selling a used computer is to erase all the personal details or information from the hard disk or drive. Instead of just putting them in the trash folder it is very important to purge all the personal data from the computer’s memory, even invisible backup files can cause danger. A tech savvy person’s help can be got if the seller does not know how to do it. If not done it may lead to accessing the bank accounts, or emails by any unknown person leading to identity theft. For that when there is a remedy. Unused scanners, printers can also be bundled with the sale of the used computer. A buyer may sometime value it. The benefits or features of the computer can be highlighted for better sales.

How to Sell Used Computers is a post from: Provins Sirock Technology Site

You can purchase a dunk tank online
You can purchase a dunk tank that is going to put someone on the spot, and into the water. You can find dunk tanks that are one seaters and two seaters if you want. There are dunk tanks that you can fill with water, and then drain for storage so you can use it again later. There are also dunk tanks that you use your own tub at the bottom of the box so that the dunk tank is shipped without that portion

A dunk tank that is sold without the tank on the bottom can be complete with the use of your own water barrel or dunk tank added to the mix. All you have to do is make one out of wood or you can find a huge plastic container. Sometimes even the small plastic swimming pools that are used as ‘baby’ pools in a families back yard is all you need in the dunk tank. Some dunk tanks come as a complete plastic box so you can fill it with balls, worms, dirt, water or what ever you might like to pay to have someone dunked into the bottom of the dunk tank.

If you want to raise money, the best way you are going to do this is by putting someone in the dunk tank that no one really likes, or at least someone of authority. If you put someone in the dunk tank, like a principal, or a commander, or someone that is generally in charge or what other people do during the day, you will find more people are going to pay to play at the dunk tank.

You can also fill the dunk tank with water, and put a pretty girl in the dunk tank. Men and boys are going to want to see the girl in a wet shirt, so they are going to pay to have their chance at throwing the balls at hitting the target to sink the girl. This is a great fund raising idea, you pay once for (the dunking tank) that you can use again and again, at additional fundraisers, for other events, and when you want to throw parties and have a great time.

Dunk Tank Fun is a post from: Provins Sirock Technology Site

A key value in the show standby command is the priority. The default is 100, and the router with the highest priority will be the primary HSRP router. We’ll raise the default priority on R2 and see the results. R3 is currently the Active router and R2 the standby, so let’s raise the priority on R2 and see what happens.

R2(config)#interface ethernet0

R2(config-if)#standby 5 priority 150

R2#show standby

Ethernet0 – Group 5

Local state is Standby, priority 150

Hellotime 4 sec, holdtime 12 sec

Next hello sent in 0.896

Virtual IP address is 172.12.23.10 configured

Active router is 172.12.23.3, priority 100 expires in 8.072

Standby router is local

1 state changes, last state change 00:14:24

R2 now has a higher priority, but R3 is still the active router. R2 will not take over as the HSRP primary until R3 goes down – OR the preempt option is configured on R2.

R2(config-if)#standby 5 priority 150 preempt

1d11h: %STANDBY-6-STATECHANGE: Ethernet0 Group 5 state Standby -> Active

R2#show standby

Ethernet0 – Group 5

Local state is Active, priority 150, may preempt

Hellotime 4 sec, holdtime 12 sec

Next hello sent in 1.844

Virtual IP address is 172.12.23.10 configured

Active router is local

Standby router is 172.12.23.3 expires in 10.204

Virtual mac address is 0000.0c07.ac05

2 state changes, last state change 00:00:13

In just a few seconds, a message appears that the local state has changed from standby to active. Show standby confirms that R2, the local router, is now the active router – the primary. R3 is now the standby. So if anyone tells you that you have to take a router down to change the Active router, they’re wrong – you just have to use the preempt option on the standby priority command.

Another vital part of HSRP configurations is knowing how to change the MAC address of the virtual router, as well as interface tracking. We’ll look at those features in the next part of my HSRP tutorial!

Cisco CCNP / BCMSN Exam Tutorial: Changing The Active Router In HSRP is a post from: Provins Sirock Technology Site

- Errors in the core communications of the network applications
- Availability of remote hosts
- Network traffic and congestion

Technical details:

Internet control message protocol is part of the Internet protocol suite as defined in RFC 792. ICMP messages are generated in response to errors in IP (as specified in RFC 1122) or for diagnostic or routing purposes.

ICMP messages are generated at the IP layer. Though ICMP messages are transferred within normal IP datagrams, ICMP messages are usually processed as a special case, different from the usual IP processing. In many scenarios, it is essential to inspect the data contained in the ICMP message and output the correct error message to the application which generated the original IP packet.
Many commonly used network utilities are based on ICMP messages:

The best known example of using ICMP is the ping function, which uses ICMP to query remote hosts for response and overall server latency. The ping function is implemented using the ICMP “Echo request” and “Echo reply” commands.

ICMP also supports the traceroute command, which is used to identify intermediate “jumps” between a given client and server. The trace route command is implemented by transmitting UDP datagrams with specially set IP header fields, while looking for the total time taken for the response to reach the original transmitter.

ICMP is a post from: Provins Sirock Technology Site

Here are 5 tips for designing your small business Web site, even on a budget:

Tip #1: Make sure your Web site loads in 5 seconds or less: Have you ever tried to view a Web site only to find that it takes 10 or 20 seconds to come up on your screen? Unless it has been recommended by a friend or you have some other burning desire to visit the site, you probably likely gave up and moved on. The first 5 seconds is very important in terms of the attention span of your visitor. During that period, you need your site to load and for the visitor to be able to “get” what your site is about. If it takes longer than this, your visitors will run out of patience and leave. Tip: if you want to show off a long flash presentation, try featuring it on a page other than the home page.

Tip #2: Limit the menu bar to 5 options: Your Web site needs to be singular in purpose and focused in appearance. If your site is trying to be all things to all people, it will end up being of value to almost nobody. The simplicity and focus of your site design is reflected in your navigation and symbolized on your home page by your menu options. If you believe your site requires more than five menu options, make some of them sub-menus that are available only after the user selects one of the five main options.

Tip #3: Make clearly visible a call to action: Ever shopped at an IKEA? Their stores have a non-traditional layout that allows you to look around freely and yet literally leads you from one section to another, right on through to the multiple cash registers and food goodies waiting for you at the end of your path. Let this serve as a model for how to set up your Web site: on every page, you need to make it abundantly clear to your site visitors just exactly what it is you want them to do. Do you want them to contact you? Order your product or service? Add a comment to your Web site? Whatever it is, make this call to action very easy to spot both textually and graphically from anywhere on the site.

Tip #4: Provide free and clear access to additional help options: You do not want to lose sales (or visits, or whatever your goal for your visitors maybe be) just because you failed to give someone the chance to ask a question. Just as with your call to action, make it clear to visitors that no matter where they are on your site they can easily locate help via phone, e-mail, live chat, call back, user forum, or knowledge database. Hint: present the various options in a prioritized manner depending upon anticipated user needs.

Tip #5: Show consistency among other design elements: The look-and-feel of your site as a whole is really just a combination of all of its individual components. Pay close attention to every detailed component of your new site. Use appropriate colors and graphics, pay attention to font size, make sure your messaging is readable and makes sense, and make sure images look crisp and appealing. Items that you think are minor might form the basis for whether someone chooses to stay on your site or find that of a competitor.

Whether you are designing your own site or hiring a professional designer, pay attention to these items and you will have a winning site for your small business, even on a budget.

Affordable Small Business Web Design – 5 Tips is a post from: Provins Sirock Technology Site

ANTI-VIRUS & ANTI-SPYWARE – For each of these, a log record to show that they were run can be helpful. Otherwise, how do you know when they were last run? How can you ensure that they are run at least once each week? How can you tell who ran the maintenance on a PC in case there is a question about a problem?

PERFORMANCE – If you have a log an objective measurement of the performance of your PC, you could compare other PCs to it to determine whether there might be a problem within a particular model of PC. You could tell whether the performance of a specific PC was deteriorating. You could use it to pro-actively determine, when the test time exceeded a parameter, that there might be malware on the PC.

IP ADDRESS – When you find a problem that exists on or comes from a PC, you may find the IP address and want to know where that PC is located. If you track the current IP address, you can find the PC in question from your log entries rather than making a visit to each PC in order to get the IP address.

DISK SPACE – In order to run disk defragmentation effectively, you need to have about 20% of the disk space available. If you log the amount of disk space remaining, you can be pro-active about efficient disk defragmentation and planning for upgrades of disk capacity.

DISK CLEANUP & DEFRAGMENTATION – Log the fact that these maintenance items were run. As simple as the tasks may be, they may give you clues to whether your PC is performing poorly because these elements of maintenance were not performed or whether there is a more serious problem.

SUMMARY – It is time to become pro-active about PC maintenance and to begin PC maintenance management. Rather than a passive process in which you run several maintenance tasks, track the results and observe them. A log can give you great clues to tell you about your PC and to help to protect it to avoid problems.

Copyright, 2006 by Tim Flynt. All rights reserved.

Tim Flynt has over 25 years dedicated to efficient application and utility systems. Experienced in higher education, entertainment, and software development organizations. Current interest in “PC Maintenance Management.” http://AcceleratedOffice.com

Condoms for Your PC – Log Your PC Maintenance is a post from: Provins Sirock Technology Site