Dynamips - IDLEPC value changing?

Hi everyone who uses the wondeful DYNAMIPS program.

Last night I set up my Dynamips config which consists of 6 rotuers and a frame relay switch. Nornally, when I tinkered with this before putting any real settings in, I was able to get my dynamips process using under 5% when all the stuff is just sitting there with no config. However, last night, once I got the frame relay going, and the settings in, the dynamips CPU usage jumped up again to 99%, everything chugged slowly, and the CPU usage would not go back down.

Have any of you that use dynamips noticed this? Does it make sense to search for a new IDLE PC value

: I was kinda surprised that a new value might be needed now.

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Comments

EdTheLad

Yes, maybe your processor and ram cant handle 5 instances.Try 4 and see will it go to
100 % or settle around 70 or 80.On my laptop i can only manage about 3 routers.The more interface cards etc you have the more demanding dynamips is on the processor.

Jammywanks

My laptop is a P4 1.8GHz mobile, 768MB of ram. I have three 3640 routers running, my idlepc value is set in simple1.net and it seems to work, but I have not setup anything in the configs yet... how many do you think I can handle with a good idlepc value?

I need switch IOS images... bbl.

mikej412

With a similar desktop (not mobile processor) I could easily run 3. The 4th one would load and work -- depending on what I was configuring.

Jammywanks

oh I just tried to load a .net lab of 6 3640 routers. That didn't go so well

The laptop heatsink fan was on full blast and the heat was so hot I could burn myself. Only two of the routers responded to get to initial configuration, the rest of them I could telnet to, but no output would show up, its like they never booted...

Things really crawl to a halt with 6

mikej412

Did you use uncompressed images? Did you start them one at a time? Did you try any other idlepc values -- I've had one of the recommended values work better than the other recommended values.

If you are using Dynagen, you can also suspend and resume routers -- so durning "router startup" when you have a lot to do you can suspend the already loaded routers to free up CPU cycles for the booting router. You can also load and suspend /all while you are studying to give the laptop a chance to cool down -- and then resume when you need to try something. Even for CCIE level stuff I usually don't need more than 4 or 5 five routers at one time (and its usually less) unless I'm working on a full 8 hour lab.

When you get a blank telnet session it could be that you just need to hit return a few times to get its attention. When I did a start /all one time and got the blank telnet sessions, I gave up after about 20 minutes and started them individually.

If your laptop does max out at 4, don't forget that you can split your practice routers between multiple machines with Dynagen, so if you have another laptop or old desktop machine you can off load a couple of routers there. I think I saw someone post that if you do a simulated frame relay cloud, try to keep those routers on one machine -- but if you use an router and configure it as a frame-relay switch, then you can split the routers that use frame-relay over multiple machines.

Jammywanks

Yes I am using unzipped images renamed the extension to .image and it seems to speed up boot times.

However I did try to distribute the load across two computers, I have a Dell laptop and Compaq laptop, but I can't get both clients connected to the server at the same time, it only works one at a time. If I try to get the other laptop running, it won't connect to the dynagen server until I close the other client. I don't know how to get it running, and the tutorial is a little vague on some questions about setting up the multi.net multi server mode.

mikej412

New Dynagen/Dynamip version on Feb 18th.... support for the 2600-2600XM series routers.

Jammywanks wrote:

I can't get both clients connected to the server at the same time, it only works one at a time.

It's pretty easy to get the multiserver running -- once you read the tutorial a few times, and find the important tidbits. I missed using the local IP address on my first attempt in my net file -- which meant the routers started and I could telnet to them, but the routers on different machines couldn't talk to each other.

Here's a multiserver test net file for 2 XP machines..... start the dynamips server on each XP machine, then run the net file on one of the machines. Adjust the IPs, working directory, and image names to match what you have. I've got idlepc values stored in the db (ini file).

autostart = False

[192.168.200.41]
    workingdir = \Program Files\Dynamips\sample_labs\MY_multiserver_test\working
    
    [[3640]]
        ghostios = True
        image = \Program Files\Dynamips\images\c3640-jk9o3s-mz.124-5a.image
    
    [[ROUTER A1]]
        s1/0 = B1 s1/0
        s1/1 = A2 s1/0
        model = 3640
    
    [[router A2]]
        model = 3640

[192.168.200.181]
    workingdir = \Program Files\Dynamips\sample_labs\MY_multiserver_test\working
    
    [[3640]]
        ghostios = True
        image = \Program Files\Dynamips\images\c3640-jk9o3s-mz.124-5a.image
    
    [[ROUTER B1]]
        s1/1 = B2 s1/0
        model = 3640
    
    [[router B2]]
        model = 3640

The key thing is to run the dynamips server on each machine, but only one net file. You control all your routers (local and remote) from that one dynagen window.

Network successfully started

Dynagen management console for Dynamips

=> list
Name       Type       State      Server          Console
A1         3640       stopped    192.168.200.41:7200 2000
A2         3640       stopped    192.168.200.41:7200 2001
B1         3640       stopped    192.168.200.181:7200 2002
B2         3640       stopped    192.168.200.181:7200 2003
=>
=> start /all
100-C3600 'A1' started
100-C3600 'A2' started
100-C3600 'B1' started
100-C3600 'B2' started
=> list
Name       Type       State      Server          Console
A1         3640       running    192.168.200.41:7200 2000
A2         3640       running    192.168.200.41:7200 2001
B1         3640       running    192.168.200.181:7200 2002
B2         3640       running    192.168.200.181:7200 2003
=> telnet /all
=>

Jammywanks

mikej412 wrote:

The key thing is to run the dynamips server on each machine, but only one net file. You control all your routers (local and remote) from that one dynagen window.

See, thats just totally not made clear in the tutorial man! Why couldn't they just specifically say that to start!!?!??! Ahh anyways at least I even managed to get once instance running stand alone. I will give this a try today. Thanks for the help.

mikej412

Jammywanks wrote:

See, thats just totally not made clear in the tutorial man! Why couldn't they just specifically say that to start!!?!??!

I think it discourages people who only want the "easy way" from using it to get the CCNA (and beyond).

You took the time to try it, research it, and finally ask -- so you are worthy!

But I'd rather have Chris and Greg spending their time advancing their "products" (Dynamips and Dynagen). As long as they don't have too many typos in the docs and fix any doc omissions -- I'm happy. Maybe someday Cisco will give them both jobs and turn their technical writters and editors loose on the docs and turorials....

Jammywanks

mikej412 wrote:

Jammywanks wrote:

See, thats just totally not made clear in the tutorial man! Why couldn't they just specifically say that to start!!?!??!

I think it discourages people who only want the "easy way" from using it to get the CCNA (and beyond).

I see what you mean, but in little time there will probably be all these automated gui systems doing it for you and next thing you know, simulators will be obsolete and all the new comers will have it easy with dynamips

I think thats probably why you can only crack WEP/WPA1 with linux

mikej412

You caught me editing.....

If Cisco never hires those guys.... then I guess someday Dynmips and Dynagen (and maybe the "new" GUI interfaces) will be "stable and mature" -- then they will have to decide if they should release it to the masses.

I like the idea of A bootable Linux CD with Dynagen/Dynamips (over at groupstudy) -- but I will admit I'm worried about how it could be used.....

Jammywanks

Yeah I'll admit its way cool and also way so powerful.

By the way it does require actual IOS images to run, which may be a road block to some, but with this emulator becoming more popular, then people will just release them on cough cough torrents, etc.

optimus

I just popped in 1 GB more of CAS 4 RAM into my machine, to make it a total of 2 GB of RAM.

I did notice a performance improvement.

The routers load faster and the program does not seem to hang as much now. Perhaps DYNAMIPS really needs some serious power to run. The routers are practically 100% the way they operate under normal conditions, replicating the MIPS processor functionality. This is the price you pay I suppose for such functional excellency.

NetworkGod

i'm running Dynamips on 4 machines
2.4ghz 512RAM (laptop)
3.2ghz 1GB RAM (laptop)
3.2ghz 4GB RAM (server)
3.2ghz 512GB RAM (workstation)

BSCI is no joke.