What is Cisco IOU? Shortly: It is a Cisco IOS running on UNIX/LINUX platform.
Actually it was intended for Cisco internal employees for tests and experiments for new features in Cisco IOS. You can find in internet a lot of IOU images and emulate Cisco Switch in GNS3 (L2 and L3). How and where to find such images is out of scope in this topic. Here is about how to install license in GNS3 to make IOU image working.
So you found some image and installed it in GNS3:
Now you have added this device to your topology and want to start it, but you will get licence error:
License section not found in iourc file
No wonder, there is no licence configured for IOS on UNIX:
Short instruction how to generate and install licence:
- You have to open your GNS3 VM shell and download IOU licence keygen:
wget http://www.ipvanquish.com/download/CiscoIOUKeygen3f.py
- After downloading run script as follow (probably you will need to install python3 firstly):
python3 CiscoIOUKeygen3f.py
- Now new file
iourc.txthas been created. As next just copy the whole text from this file and paste it to the GNS3 settings „IOS on UNIX“ -> IOU licence:
- After applying the changes you can add IOU device to your topology and start it. Enjoy:)
Cool stuff