Lethe's Ccielogs

Hello all, today surfing the net I've found an interesting article by Wendell Odom, and if you're in the Cisco/Networking field I don't need to spend any other word about him, where he talks about the new and updated CCIE V4 Lab. As you know Cisco recently announced a major update to the CCIE Lab which I've already talked of in another post, he written "changes" have been become effective this week while some people already started talking about the beta lab Odom among them.

Here you can read the full article and the author's first impressions.

Hope you'll find it useful,

Lethe.

 

Not properly a technical post anyhow I think important. This morning I went Amazon for shopping some books and noticed Ciscopress is going to publish the fourth edition of their CCIE Routing and Switching Exam Certification Guide which as you know is an invaluable for anyone preparing for the new CCIE R&S lab. The book is scheduled to be released for early October and it’ll have the same style of other Ciscopress books and it’ll include some new content like :

- BGP Routing Policies (I already love this part!)

- An Extended QoS coverage

- An Extended WAN coverage

- More MPLS

- IPV6 redistribution (aye!) 

- Troubleshooting and Network Optimization

It’s already available a rough cut edition via Safari subscription here I’ll try to get a copy and eventually will write something more about it, for now I’m really excited about this new release, it seems my shopping will wait for some time until this book is published.

Cheer Lethe.

Did you hear the latest new? Cisco did it again  They announced an upcoming change to the actual CCIE R&S exams blueprint, the new version of the exam/lab is scheduled to go live after October 18th

I think this is an exciting new for every CCIE-Wannabe (like me) as a lot of new stuff will appear in the V4 of the certification and some else will be removed, you can find all the details on Cisco’s website but here’s justa  few hints about what is gonna change : 

- First of all Cisco added a brand new section dedicated to troubleshooting, reading through an interview to Maurilio Gorito (Content Manager for the CCIE program) I’ve noticed Cisco is trying to make the lab more "job" oriented in the sense they’re trying to test real world problems and skills used in network engineering.

- Cisco is going to change the list of equipment used to prepare for the new revised exam

- Open Ended questions, or Core Knowledge questions if you prefer are there to stay  

I think the list of new and updated things in the lab is too long for a single post and you can easily read a lot of good articles on Cisco’s website here, attached to this post you’ll find a pdf describing the upcoming changes to blueprint in rgeater detail.

Well what else if not happy studying and best of luck in your CCIE adventure!

Lethe.

Hello all before finally today I received my 24 Units rack so I guess it’s time to cable all my lab again! This is a great news for me as I’ve been “labbing” using routers on my desk or on the floor, yes I know that’s not professional but that was the only way for me to have all routers handy, the bad part of this is I have to spend lot of time on configurations/cabling but I think it’ll be well worth the effort.

Today I’ve assembled the rack pieces, I think it was the IKEA model, and next week hopefully I’ll be putting all the routers on it so I can finally have a stable and well cabled lab, trust me it really sucks to have tons of cables and routers around your room…

I’ll be using a two pods topology with 2 backbone routers, 1 frame relay router and 8 “remote” routers divided into the two pods, this should give me all that I need to keep testing routing and switching stuff.

Below you can find the detail of the topology I’m going to build :

If you, like me, have used BSCI self study guide to prepare for BSCI CCNP exam this picture should be familiar  As soon as I have some spare time I’ll be building and publish this exact topology for you GNS3 fans out there. If you’re wondering why I’m going to use two pods instead of one, well I don’t want to ruin the surprise so I’ll just tell I’m preparing a surprise for all of you preparing for the CCNA exam.

Well time to run as my BCMSN exam is approaching and I still need to practice a few stuff and tomorrow I have class.

Lethe.

What I want to show you on this post is how to add a PC to our "virtual" Dynamips topology, why you’re wondering? Well for testing our topology my friends, you could, of course, use a real computer or simply add another router to your topology but why wasting resources when all we need is a box being able to use ping or traceroute just for testing purposes?

All you need is to download a software called Virtual PC Simulator which is a free software that runs both under Windows and Linux systems and can be found here . Once you’ve downloaded the software extract it somewhere on your computer and launch it (vpcs.exe) a dos window will open up if you need help using VCP just type a ? for instructions :

VPCS expect a file named startup.vpc in which is defined the startup configuration of your virtual hosts, you can easily edit this file with your favorite editor to suit your needs (notice the editor I’m using here yeah that’s VI for Windows ) :

In case you don’t like to edit configuration files as I did you can simply use the command ip to assign an IP address and default gateway here’s an example :

ip 10.0.0.5 10.0.0.1 24

This will assign the ip address of 10.0.0.5 in the 255.255.255.0 subnet with a default gateway of 10.0.0.1. Ok now let’s integrate VPCS into our GNS3 installation.

First off open up GNS3 and select Symbol Manager under the Edit menu when the Symbol Manager window appear on the left pane select Computer and double click it to add to the right pane of Customized nodes. Under Customized node settings type a name of your choice, I opted for Computer what a fantasy, and be sure to select Cloud under Type :

Back to GNS3 main page a Computer icon should have appeared between the available Symbols, drag a computer in your internetwork and right click on it and select Configure and input what in the figure :

Now connect your PC to the switch, check my previous post if you’re in doubt on how to create a link between two devices. Basically what we’ve done is configured each computer as a cloud that connect to GNS3 via UDP ports designated. Now all you have to do is to configure the PC with the proper IP address, if you’ve not done that yet, and configure the proper interfaces on the routers so that you’ll be able to ping/traceroute connections in your internetwork.

 

If there’s something that I find really annoying about GNS3 under Linux is the fact it uses, by default, the *cough* ugly *cough* xterm application for the console access to the virtual routers, aesthetic problems apart there is another little annoyance about this, Fedora 10 does not install xterm by default so you have to install manually.

In the, fantastic, GNS3 basic tutorial the author explained how to configure the program Konsole for err… console access (no that’s not a typo) but I don’t use KDE as my desktop manager and my distro it’s not Ubuntu (eeek) so I don’t know how Fedora named the package, forget about it I’m not gonna install KDE just to have a fancy looking Console.

In this post I’ll show you how to setup putty, the nice and tiny ssh/telnet client, for console access on your linux box, yes finally you can trash that *ugly* xterm!

First of all open up GNS3 and access the Edit –> Preferences menu :

Now simply anything eventually in the "Terminal Command" box and replace it with :

/usr/bin/putty -fg green -bg black -telnet %h %p

Congratulations now you’ll have a fully featured, and very very professional!, putty console access with Green characters on black screen like the one I’m using :

Nice motd eh Well that’s all folks you finally have a really professional putty console access!

***UPDATE*** I’m sure you’ve figured out this yourself but just in case, in Windows environment Putty is the default console access program all you have to do is to download putty (here), copy it somewhere and tell GNS3 where it is. I don’t use Windows much so I could be wrong but I’ve noticed the Windows version of Putty does not support the –fg and –bg switches to set foreground and background colours so you’ll have to setup putty manually. Again I don’t use Windows so if you know how to do that drop me a line I’ll be glad to update the post . 

Thanks for reading this, until next. Lethe.

 

In my last article I briefly introduced you to Dynamips and GNS3 and explained you how to install and run for the first time this wonderful software.

In this article I'll describe in deeper detail the configuration of GNS3 and will explain you how to build a fully working topology for your CCNA/CCNP lab. Before we start let me list the different model of Cisco routers supported in Dynamips, this is to help you to download the right version of IOS :

1710 1720 1721 1750 1751 1760 2610 2610XM 2611 2611XM 2620 2620XM 2621 2621XM 2650XM 2651XM 2691 3620 3640 3660 3725 3745 7200

Ok for the purpose of this post I'm going to use a 7200 image but keep in mind you can use any image that you like (at home I'm running lab with 2611XM images, the same I have on my "real" routers). For our example we're going to build the following topology :

  

Looks great eh? Ok let's get to work and start building the topology!

Ok before we begin to build our topology we need to calculate the "idlepc" value for the particular IOS image we're going to use, this is very very important, we need to let GNS3 calculate IDLE PC values for our routers, as you have noticed when you started the routers your CPU usage jumped to 100% near that (the picture is from one of my notebooks an HP Pavillon with AMD64 Turion processor and 2 GB of memory) :

This is because Dynamips, the core emulator running under GNS3, does not know when the virtual router is idle, and when it is performing useful work. The “idlepc” command performs analysis on a running image to determine the most likely points in the code that represent an idle loop in the IOS process. Once applied, Dynamips “sleeps” the virtual router occasionally when this idle loop is executed. This significantly reduces CPU consumption on the host without reducing the virtual router’s capacity to perform real work. IdlePC values are particular to an IOS image. They will be different for different IOS versions, and even for different feature-sets of the same IOS version. However idlepc values are not particular to your host PC, operating system, or to the version of Dynamips that GNS3 is using. It is possible that Dynamips will not be able to find and IDLPC value for an image, or that the values it does find do not work. If this happens, try repeating the process again.

To determine an IDLEPC value for a given IOS, start GNS3. Drag only one router set up to use the IOS version you are trying to configure. Right-click the router and choose Start. Then right-click the router and choose Console. You may need to press Enter once initially in the Console window. When asked “Would you like to enter the initial configuration dialog?”, enter no and press Enter. Wait for the router to settle down at a Router> prompt. You may need to press Enter once or twice to get there.
After the router has settled down to a Router> prompt, return to the main GNS3 window and right click on one of your routers selecting IDLE PC and let GNS3 calculate the best IDLE PC for your particular configuration :

A few IDLE PC values will be displayed with the ones suiting your needs displaying an * in front of them, try to select the one with a lower value and click on OK. Great! we can continue to configure our topology.

Open up GNS3 and drag our three routers into the topology pane and change their hostname to something meaningful for you (I choose 3 cities I love ) by right clicking on the routers and selecting "Change hostname"

 

Now let's add the needed interfaces to our routers, for the purpose of this topology we need :

- Serial interfaces for the WAN connection

- Fast Ethernet interfaces for future use (optional)

To add interfaces simply right click on one of the routers in the topology and select Configure and then select the TAB Slots as you can see you can  configure one router at time, by selecting its "name" on the left pane, or you can globally configure all the routers by clicking on Routers, from this page select the cards to insert in the virtual slots :

 

As you can see I've added a FE interface and a PA-4T+, basically a serial interface, to our routers, of course the cards and the number of slots depends on the model/image you're using so you could see something different.

Ok now that we have our interfaces all we have to do is to connect the routers, click on the Connect button and to have a greater degree of control on the configuration select Manual this is not mandatory I use just to be able to choose which interface will be connected to what.

 

Now click on one of your router and select the interface to which the cable will be connected :

 

Now, I know you've guessed, click on the other router to select the interface and complete the connection :

 

Now click on the big red cross, aka the create a link button, to go back to design mode :

If you look at the right pane you'll see how the Topology Summary is now showing the connection we've created :

Ok let's power on our internetwork, it has routers no? so it's an internetwork You can simply right click on routers one by one and select Start or click on the Play in the too, time to open a console session to our router and start configuring them (I'll just show you the output of the show interfaces command) :

As you can see all our interfaces are there and working perfectly!

Congratulations! You've just configured your first internetwork with Dynamips now it's up to you to build your topologies and start having lot of fun in the wonderful world of networking!

As usual feel free to contact me for any question or problem about the post or more in general about your studies I'll be glad to answer asap!

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