CCIE Pursuit Blog

January 5, 2009

Dynamips for CCIE – Part 1 – What is Dynamips?

Filed under: Cisco,Cisco Certification,Dynamips,IOS — cciepursuit @ 12:05 pm

I’ve recently started using Dynamips for the vast majority of my CCIE lab study.  I had experimented with Dynamips in the past and found it very useful.  I really didn’t have a box capable of running Dynamips for full-scale labs vendor labs (IE in my case) so I used it primarily for short, “technology-focused” labs.  I recently upgraded one of my home boxes with new hardware and Ubuntu (Linux distro) and have started using IE’s Dynamips lab workbooks as well as a lot of their new Volume I labs (not specifically written for Dynamips, but easily convertible).

Anyhoo….I thought that I would share some of my experience with Dyanamips.

So what is Dynamips?  It’s basically a program that emulates the hardware of a number of different Cisco router platforms (7200, 2600, 3600).  Christophe Fillot is the author and maintains a technical blog here.  Since the software emulates the hardware you can run IOS on it and basically have a virtual router.  Better yet you can connect you can run multiple instances these virtual routers and connect them together to create virtual topologies.

Sounds great, right?  So Cisco is completely cool with this?  Actually, no.  In order to run a virtual router instance you need to have a copy IOS software to run on it.  The “letter of the (Cisco) law” states that “users may only run Cisco software on the Cisco hardware for which the user pays the appropriate fees”. This is discussed a little more in depth in this posting, but basically you are breaking your Cisco IOS terms of use by running IOS on Dynamips.  That said, it’s highly doubtful that Cisco is going to do anything about this (for a number of reasons) but I feel that it is important to let you know the “legalities” of using IOS images with Dynamips.

While Dynamips is an amazing program, it does require a lot of resources in order to run multiple instances of virtual routers.  If you’re going to use it for vendor labs, you’ll need to beef up your box.  The IE labs use 6 routers, 4 switches, a Frame Relay switch, 3 backbone routers, and a terminal server.  That’s 15 devices.  I broke down and bought a Quad core Intel CPU with 4 gigs of RAM in order to run the IE labs.  You can run smaller topologies on boxes with less horsepower.

I won’t pretend to know the reasons behind this as I’m not an OS guru by any stretch of the imagination, but Dyanmips seems to run much better on Linux than on Windows.  I am running it on Ubuntu 8.10.  You do not NEED to run Dynamips on Linux, but I’ve found (and read the same from others) much better response on Linux.

Most users do not work directly in Dynamips but rather interact with that program via a front-end program.  Two of the more popular front-ends for Dynamips are:

Dynagen – a very popular text-based Dynamips front-end.
GNS3 – A graphical Dynamips front-end (I use this).

If you’re interested in Dynamips, do yourself a favor and bookmark these sites now:

BlindHog.net - Tons of great Dynamips tips, tutorials, and labs.  Many with step-by-step videos.
7200emu.hacki.at – A very good forum for all things Dyanmip.  This is your best resouce for finding out Dyanmips information and getting your Dynamips questions answered.

Tomorrow I’ll get review installing Dynamips (actuall GNS3).

December 2, 2008

Status Update: Back From The Dead

Where I’m at? Two turntables and a micro….damn you Beck!

It’s been a bit since I last updated the blog.  I’ve been busy as hell the last few weeks.  We’re approaching an end-of-the-year “change freeze” at work.  For a little over a month, no changes can be made without [insert favorite deity here]‘s direct approval.  That’s great except that during the weeks right before the change goes into affect we get slammed because everyone is trying to install everything that they can before the change freeze begins.  We’ve also lost some staff and they have not been replaced so we’re taking on their work.  Our stock is in the crapper and the US is in a recession (since December of last year it seems).  Needless to say, work has not been fun.

On the home front, I’ve been catching up on projects that were on hold during the summer due to my studies.  Winter is now here and that means a bunch of home projects.  School is in full effect, so I have to make sure my son spends more time studying than watching Cartoon Network and playing Lego Star Wars (not an easy task).  There are also my kids’ sports and other extracurricular activities that I need to support/attend.  Throw some holidays into the mix and you’ve got an even bigger time-suck.

Did I mention that winter is here?  I fucking hate winter.  I love Minnesota, but only for 9 months a year.  I had thought that by now that I would be used to winter, but that’s not happening.  It’s a cold, dead, miserable season and it bums me out to no end.

I haven’t really been able to get good traction on my studies.  For the last few weeks I simply haven’t had the time to do much studying.  I’m still setting aside weekends for my studies, but even good chunks of those have been eaten up by on-call and other issues.  I’m losing my knowledge in some technologies.  I have done two complete labs since my failed lab attempt.  I have been working on technology-based labs, but my CLI sessions have been few and far between.

I’ve also been pulled in a number of different directions with my studies.  My boss is really stressing “convergence”.  Which, to him, means that we need to learn voice technologies.  Not how to troubleshoot existing voice implementations in our network, but rather learning generalized, low-level voice technologies.  To placate the boss man, I have been studying for the CVOICE exam.  I plan to take either that exam or the CCNA-Voice exam sometime before the end of the year.

The good news is that the worst is over.  The freeze change starts next Monday so work will quiet down.  I’m (mostly) caught up on my home projects.  I should have time available once again to jump into my studies.  I have to sit down and create a study plan and stick to it.

I recently installed Dynamips (via GNS3) on a laptop running Ubuntu.  It’s duo-core 1.5Mhz (I think) CPU with 2 gigs of RAM.  I was able to get the full IE topology running.  I now have the Dynamips Workbooks from IE as well.  Everything was rocking until I got to the BGP section of the lab.  My CPU(s) maxed out and I was seeing EIGRP neighbors randomly dropping.  I mucked about with different idlepc settings, but I couldn’t get the CPU load to drop.  I was disappointed because I really want to use Dynamips so that I have a virtual rack available at any time.  So I bought myself a Christmas gift: 

Combo w/ Intel Core 2 Quad Q6600 (2.4GHz – 1066FSB – 8MB Cache)
  Asus P5N73-AM
  Basic Fan / Heatsink
  White Thermal Compound – 1 Use Packet
  4GB – PC2-6400 (DDR2-800)
  (Dual Channel Memory Kit)
  Okia 600 Watt Power Supply (Dual Core Certified)

It cost just over $300 and should arrive this Thursday.  Of course right after I ordered this I found a tutorial on how to run Dynamips across multiple boxes.  Oh well, I need/deserve a new box anyways.  :-)

This will give me a box to run a full IE Dynamips topology on so that I can lab during any free time I get at home.  I’ll still be using my rack at work during weekends as well as occasionally renting rack time, but this should help me maximize my free moments.

Anyhoo…I’m back on the CCIE train and I will be blogging more frequently going forward.

January 17, 2008

Cisco’s Official Response Concerning Dynamips

Filed under: Cisco,Cisco Certification,Dynamips,Home Lab,IOS — cciepursuit @ 3:40 pm
Tags: , , , ,

I was reading this post at Brad Reese’s blog about installing Dynamips.  It has a link to the Internetwork Expert Dynamips COD.  It also has a picture of one of the Brians (McGahan – at Networkers?). 

The bit that caught my interest was this post concerning the official Cisco (non)response concerning Dynamips.  It seems that CertGuard believes that Dynamips may be in violation of Cisco’s IOS copyright and licensing agreement.  Cisco’s response:

As a matter of policy, Cisco will not comment on a specific customer or organization’s use of Cisco software.

That said, it is accurate that according to Cisco’s standard software licensing terms, users may only run Cisco software on the Cisco hardware for which the user pays the appropriate fees.

We have also heard from customers that emulation/simulation tools are of value to them and we are exploring different ways on how to continue to help customers best design and test network configurations prior to deployment of their networks.

Dynamips does not include IOS images so I don’t think that they really need to worry about Cisco turning the Eye of Sauron on them.  I don’t think that anyone is looking to throw Dynamips on a PC and using that to replace the 2800 routers in their network.  For Cisco, Dynamips is a boon.  It is allowing more certification candidates to get hands-on (emulated) experience with their products.  The only (extremely slight) downside to their business is the (very few) certification candidates that will be using Dynamips instead of buying new Cisco gear.  Most of that market was being served by eBay and used equipment vendors anyway.  Plus, Dynamips is absolutely free so there’s no one getting rich on the backs of Cisco.  That said, it does look like Dynamips users – by obtaining and running Cisco IOS images in Dynamips – ARE in violation of software licensing agreement.  But, considering the effect of this practice on Cisco, I don’t expect Cisco to do anything.

In the end, CertGuard’s point is interesting (and likely true) but I can’t see any harm that Dynamips does to Cisco, while I can see plenty of upside for Cisco from Dynamips.

****Update****

While Cisco is probably not affected by Dynamips “market”, vendors who currently offer simulators for the Cisco certification markets ARE going to be affected. 

January 11, 2008

Dynamips With GNS (Graphical Network Simulator)

Here’s an interesting article about Dynamips.  It’s pretty basic, but there is a nice overview of GNS3 (Graphical Network Simulator).  GNS3 looks like a very nice tool for designing networks with Dynamips.  I find it very easy just to edit the .net files, but this tool looks very promising for users that are new to Dynamips (provided that it is not buggy).  I may give it a test run just to see if I can export the graphical representations (beats making them in Visio).

January 7, 2008

Internetwork Expert: Dynamips Lab Workbook Part 2 Releasing 15 January

For all of you folks preparing for the CCIE with Dynamips, IE is releasing the second Dynamips version of the Volume II labs: 

Dynamips Lab Workbook Part 2 – Coming January 15, 2008

Internetwork Expert will be releasing CCIE Routing & Switching Dynamips Lab Workbook Part 2 (IEWB-RS-DYN-EL-2) on January 15, 2008. Internetwork Expert’s CCIE Routing & Switching Dynamips Lab Workbook Part 1 & 2 consist of all 20 labs from our CCIE Routing & Switching Lab Workbook Volume II(IEWB-RS-VOL2) which have been reconfigured to run on the open-source Dynamips IOS emulation platform.

Both parts of this workbook are available exclusively in electronic format. Part 1 consists of labs 1-10 from IEWB-RS-VOL2, and part 2 consists of labs 11-20 from IEWB-RS-VOL2. This product is targeted for CCIE R&S candidates that prefer to use Dynamips for lab practice as opposed to real live hardware. As the content is identical, candidates using real hardware in their own practice labs or via rack rentals should use IEWB-RS-VOL2 as opposed to this product.

For a detailed overview of what Dynamips is and how to use it, refer to Using Dynamips for CCIE Lab Preparation.

To pre-order Part 2 and get more information, visit our CCIE Routing & Switching Dynamips Lab Workbook page or contact the Internetwork Expert sales department.

November 26, 2007

More Memory Makes Dynamips Happy

I finally dropped a gig stick of RAM in my laptop (it was at 512 megs) and fired up Dynamips.  What a difference!!!  I’m able to run more device instances and they run much faster.  I’m going to swap out the 512 meg stick for another gig stick this weekend.  Since I’ll be doing a lot of technology specific labs this week, I’ll probably be doing most of them in Dynamips.

October 27, 2007

Internetwork Expert: Using Dynamips On The Mini Mac

Over a month ago I posted about Internetwork Expert’s plans to create a Class On Demand for using Dynamips on a Mini Mac:

Building on the strength of their excellent Dynamips for Windows class-on-demand, IE will be releasing a COD for Dynamips using the MAC OSx operating system.   This class is scheduled to be available some time during the week of 17 – 21 September.

The original dates have since come and gone, but today I see that they have a page up dedicated to using Dynamips on a Mini Mac.  No COD at this point, but lots of good information.

September 26, 2007

Dynamips Blew Up On Me

Filed under: Dynamips,Home Lab — cciepursuit @ 7:07 pm
Tags: , , , ,

It was bound to happen.  I’ve been doing a lot of labs with Dynamips using 4 routers as 1 switch.  Today I started doing some BGP labs that required 5 routers.  Dynamips kept dumping its core (ewww!).  I tried to isolate the issue to a single router instance, but couldn’t do it.  I finally realized that as soon as the IOS loaded on the 6th device (7th if you count the Frame Relay switch) Dynamips would crash.  This is probably due to my laptop.  I only have 512Meg of RAM.  I had planned to drop 2 Gigs in it,  but Dynamips had been chugging along fine up until today.

I dropped the RAM on the Dynamips router instances from 128 to 96.  I was able to get all 6 devices up and working.  Success!!!  Well….until I tried to configure BGP that is:

r1(config)#router bgp 6
r1(config-router)#
*Mar  1 00:42:45.707: %SYS-2-MALLOCFAIL: Memory allocation of 18360 bytes failed from 0x609B8D6C, alignment 0
Pool: Processor  Free: 6300  Cause: Not enough free memory
Alternate Pool: None  Free: 0  Cause: No Alternate pool

-Process= “Exec”, ipl= 0, pid= 3
-Traceback= 0x603F5B88 0x6053CC4C 0×60543434 0x609B8D74 0x60A08938 0x609B9DE0 0x
60798530 0x607999B8 0x60432DB0 0×60450578 0x604F164C 0x604F1630

I finally stripped the switch out of the equation (I just directly connected the couple of routers on Ethernet segments) and bumped the RAM back to 128.  I started each device one by one and then telnetted to it to make sure that it didn’t crash once the IOS was loaded.  I was finally able to get all 5 routers rockin and rollin with BGP and OSPF redistribution.

I put in an order for 2 gigs of RAM shortly after.  :-)

September 14, 2007

Dynamips On Mac Mini Blog

Filed under: CCIE Blogs,Cisco,Cisco Certification,Dynamips,Home Lab,Training Materials — cciepursuit @ 12:17 pm

For all of you Mac-Heads out there, Scott from the GroupStudy list is blogging about his experiences with setting up Dynamips of a Mini Mac with 4 live, eight-port 3560s as a CCIE lab.  He’s using the Internetwork Expert lab topology. 

IT Artisans’ Dynamips Blog

September 13, 2007

Internetwork Expert: IPv6, Dynamips on Mac, and Cool Shirts

Internetwork Expert just sent out their September newsletter.  There are a couple of items of interest for R&S CCIE candidates:

On 26 September, IE will be conducting the second of their four announced free V-Seminars.  This month’s topic will be IPv6.  If last month’s V-Seminar is any indication, then they will most likely record the IPv6 class and put it up on their site for on-demand viewing.  This is good for candidates who can’t make it to the live class.

Building on the strength of their excellent Dynamips for Windows class-on-demand, IE will be releasing a COD for Dynamips using the MAC OSx operating system.   This class is scheduled to be available some time during the week of 17 – 21 September. 

If you are a customer of Internetwork Expert and you pass your lab, you can send them your name, CCIE number, and mailing address and they will send you a free polo shirt with your name and CCIE number on it.  They don’t show a picture of the shirt, but I think that this is a really cool idea.

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