Idle pc gns3 how to#

net file and replace the idle-pc value found there with your new 'good' idle-pc value. net files) that have used this IOS, open the. Now GNS3 will automatically use that value in any NEW topologies you create.

Select the image you are using and check the IDLE PCs value

Idle pc gns3 how to#

Now that you have a good idle-pc, you need to know how to use it well.įirstly, check that GNS3 has recorded you best value against the image you are using If you have an idle-pc vlaue that shows less than 10-15% CPU, you may want to go to step 6, WRITE IT DOWN next to the Idle-pc value you wrote down in step 4 If MULTIPLE values appear with *, WRITE THEM ALL DOWN (in a column)Ĭheck the CPU utilisation for dynamips in the task manager or console window.Įstimate the average CPU consumption for dynamips over say 15-20 seconds When you find a value marked with a *, WRITE IT DOWN If NO values appear marked with *, try again In GNS3, right-click on the router and choose idle-pc Take note of the amount of CPU being chewed by dynamips NOTE: While writing this post, I observed this step alone dropped the CPU usage from 98% to 1% on a Windows 7 install (running in a VM on OS X)īack at your task manager or console window: When when the router is fully up, configure the following: In GNS3, start a new topology with 1 router ONLY Keep this window visible for the entire process

Mac OS X: Open a terminal window and enter the command top -o cpu

Linux: Open a console window and enter the command top Windows: Open the windows task manager and sort by %CPU REPEAT FOR EVERY DIFFERENT IOS IMAGE YOU WISH TO RUN ON YOUR SYSTEM: Here is my tedious and time consuming method of finding a good idle-pc value. Try to ignore it, and you will be forever miserable. Get it right, and you will have a great GNS3 experience. One of the most difficult problems new users have to come to grips with when starting out with GNS3 is the concept of an Idle-PC.