Category Archives: GNS3

GNS3 – Using a Router Image as a “PC”

I started to use GNS3 to assist in studying for my CCNA, and once completed with the CCNA, I will move onto the CCNP cert which will have new courses\tests starting in Feb 2015.  GNS3 does have provisions for a “Virtual PC System’ in the software; however, I feel that I wanted\needed a platform that has more capability to ensure proper configurations of the scenarios.

To solve this issue, I use a router image as the end point (PC function) in the practice scenarios, and it is rather easy to config a router for this function.  The advantage of using a router is that it has a lot more functionality than the VPCS provided, and you should be very familiar with the commands for the Cisco IOS.

To create a PC from the router IOS, there are a few simple steps to follow.

1. Drag and drop a router image into the scenario

gns3 router

2. Right click on the router, select change icon and select the PC icon

GNS3 Change Symbol           GNS3 Change Symbol2

3. Right click on the new PC icon (previously the router icon) select configure and rename it from Rx to PCx.  The element has to be in the “stopped” state.

GNS3 Config    GNS3 Config Screen

4. Now the end-point looks like a host, so I make a couple config changes.  In global config execute the “no ip routing” command and “ip route 0.0.0.0 0.0.0.0 <default GW IP>