Cisco Dynamips images (Cisco IOS)

Versions this guide is based on:

EVE Image Name Downloaded Filename Version vRAM Idle PC
c1710-bk9no3r2sy-mz.124-23.image c1710-bk9no3r2sy-mz.124-23.bin C1710-BK9NO3R2SY-M 12.4(23) 96 0x80369ac4
c3725-adventerprisek9-mz.124-15.T14.image c3725-adventerprisek9-mz.124-15.T14.bin C3725-ADVENTERPRISEK9-M 12.4(15)T14 256 0x60c08728
c7200-adventerprisek9-mz.152-4.S2.image c7200-adventerprisek9-mz.152-4.S2.bin C7200-ADVENTERPRISEK9-M 15.2(4)S2 512 0x60630d5c
c7200-adventerprisek9-mz.152-4.S6.image c7200-adventerprisek9-mz.152-4.S6.bin C7200-ADVENTERPRISEK9-M 15.2(4)S6 512 0x62f224ac


Other then in the above list versions were NOT tested and might be NOT supported.

IMPORTANT! Make sure you are using US/EN keyboard on your terminal.

SSH to the EVE to obtain cli access, and create temporary directory abc.

mkdir abc
Upload original Cisco image binary file to temporary directory abc. The best for upload  is FileZilla or WinSCP. Using EVE CLI, uncompress original image. Output file extension must be .image. Be sure you are using properly your source and output filenames.
cd abc 
unzip -p c1710-bk9no3r2sy-mz.124-23.bin > c1710-bk9no3r2sy-mz.124-23.image 

Move uncompressed image to destination folder:

mv c1710-bk9no3r2sy-mz.124-23.image /opt/unetlab/addons/dynamips/

Clean and fix permissions:

rm -rf abc
/opt/unetlab/wrappers/unl_wrapper -a fixpermissions

Calculating IDLE-PC:

First time it is recommended to check Dynamips image IDLE PC usage.

Run your image from main EVE cli. Enter one of the following commands below. Be sure you have use right image name in the command.

dynamips -P 1700 -t 1710 /opt/unetlab/addons/dynamips/c1710-bk9no3r2sy-mz.124-23.image
dynamips -P 7200 /opt/unetlab/addons/dynamips/c7200-adventerprisek9-mz.152-4.S7.image
dynamips -P 3725 /opt/unetlab/addons/dynamips/c3725-adventerprisek9-mz.124-15.T14.image

Wait for the following line on the console:

Would you like to enter the initial configuration dialog? [yes/no]:

Exit from initial configuration dialog, and quit to get the con0 prompt:

Router con0 is now available

Press RETURN to get started.

Press Enter to get to the router’s CLI:


To check CPU usage from EVE cli, open another new ssh session to the EVE. Enter CLI command top.
CPU usage is very high, a whole CPU for each instance:
root@eve-ng:~# top 
 3521 root      20   0  412236 125408 109904 S 99.5 25.4   3:27.82 dynamips

Go back to router session and press two key combo ” ctrl + ] ” release keys, and then press key ” i ” Dynamips will calculate suggested Idle PC values:

Please wait while gathering statistics...
Done. Suggested idling PC:
   0x80369ac4 (count=35)
   0x8023afac (count=51)
   0x8023b008 (count=30)
   0x8023b050 (count=27)
   0x803637a0 (count=38)
   0x80363984 (count=20)
   0x80363ccc (count=28)
   0x80363d48 (count=28)
   0x80363d78 (count=74)
   0x803645d0 (count=76)
Restart the emulator with "--idle-pc=0x80369ac4" (for example)
Usually the highest value of IDLE PC will best for your CPU. In the calculation above it is 76. Copy value of IDLE PC to the notepad and we can start test best value fit for your Dynamips node.
To stop dynamips router calculation mode use:Key combo: ctrl + ] ” release keys, and then press key ” q
Go to EVE WEB GUI, add your Dynamips node and change IDLE PC value to calculated, save and start node.

Check your CPU with top command (cpu check section above)

If CPU usage is lower, then a good IDLE PC value has been found:

 3598 root      20   0  346700 125328 109828 S  5.3 25.3   0:03.98 dynamips

If CPU is still high, then another value must be tested.