[Cisco + GNS3] Configuring IOS in GNS3

1. Open the GNS3 Simulator

2. Select Edit->IOS images and hypervisors, a new window appears

3. Under the Settings in IOS images tab, in "Image file", input the IOS image for your router, it should be a .bin file. I can't provide any of those images but you can search Google for "cisco IOS images".



4. Create a new file called "baseconfig.txt", insert this script in it:

!

hostname %h

no ip domain-lookup

line con 0

exec-timeout 0 0

logging synchronous

! and if you never want to have to type "enable" again, add:

privilege level 15

! And I also like to add:

service timestamps debug datetime msec

alias configure show do show

alias interface show do show

line vty 0 15

no login

exec-timeout 0 0

logging synchronous

privilege level 15

5. Select path to baseconfig.txt which we have created before, in the "Base config".

6. Platform,model, and default ram will be inserted automatically by GNS3.

7. If you have finished the configuration, save it. Close.

8. Go to Edit->Preferences, check whether all configuration is correct. 

9. Go to the Qemu tab, click the Test button. 

If you get an error "qemuwrapper path doesn't exist". Just search for qemuwrapper.py in your system in linux it would be /usr/share/doc/gns3/qemuwrapper.py. Set the configuration to the correct path to qemuwrapper.py.
If you get an error "failed to start qemu", then install qemu (sudo apt-get install qemu), then set the "path to qemu" and "path to qemu-img" to the corect path where the qemu is installed.

10. Go to the "Qemu host" tab, if you don't want to use any qemu or virtualbox guest images, just download and use the VPCS image for a lightweight OS just for GNS3. 

11. Done.