To remedy this, you can supply Dynamips with an Idle-PC value, to consume less CPU. When Dynamips runs an IOS image, a single instance can consume 100% of the processing time for a CPU core or thread. We really recommend using the c3640, c3660, c3725, c3745 and c7200 IOS images listed below, they have proven to be the most stable in GNS3 provided you use the right amount of RAM and Idle-PC value. From experience you can usually use a bit less RAM just fine. The minimum RAM is the amount of memory needed for IOS to work at maximum capacity with most feature configured and activated. We recommend Mainline over Technology train if you are interested on stability without the need of new features.Please see Cisco IOS Versions and Naming for more information. You will find the technology train images to contain the newest features but it may also contain the most bugs.

Should I use a mainline and technology train image? # Please note that the IOSv appliance is based on IOS 15 and there are IOU (IOS on UNIX) images with IOS 15. All other platforms are now end-of-life and only support IOS 12.4. Only the c7200 series get newer IOS 15 images.

Currently, the c7200 images are the only ones still available for download for those with a support contract.

R+Svms are all vendor Routing and Switching images that are larger in size but can be imported into GNS3 for real world network emulation.ĭue to these platforms hitting End of Sale, End of Life, and End of Support status, the images are no longer available for download from Cisco’s support sections.

IOS images are lower in cpu and memory so you can fit more of them in one topology.

IOS images are usually run in Dynamips however R+Svms are housed in a virtual machine.

What are the differences? Here are the major differences:

These are classified as Routing and Switching virtual machines (or R+Svms) for short. In the new GNS3 1.4, there is a way to run a second category of switches and routers. For older images, we use and maintain Dynamips an emulator dedicated to emulate some Cisco hardware. GNS3 offers multiple ways to emulate IOS. Configure GNS3 to use an additional remote server.How to use applications with the GNS3 Web interface.Install an appliance from the GNS3 Marketplace.

Cisco images for gns3