Cisco IOS on Unix, also known as Cisco IOU, is released for internal Cisco use only. IOU permits to run IOS natively on x86 platform while GNS3 must emulate the whole hardware. The big difference is that IOU can run more IOS instance than GNS3, but GNS3 can run real IOS version. The purpose of this article is to let you know how IOU can be integrated with GNS3 emulator software to practice switching concepts.
**Pay Attention:** Cisco IOU binaries are not for public use. If you are a Cisco guy you must ask your company how you can get IOU binary files and license. Other do not have rights to use IOU images.
Make sure you have...
Before we start I want to make sure that you all have the required tools and softwares. I have listed down them with download links below,
GNS3 - http://www.gns3.com
Virtual Box 4.3.12 (I had some bad experience with version 5.0, Check my article to know more VirtualBox EFAIL error) - https://www.virtualbox.org/wiki/Download_Old_Builds_4_3_pre24
IOU Images - As already mentioned, strictly for Cisco guys! But still you might get these images by Googling!
GNS3 IOU VM - Available from sourceforge, I downloaded and used a older version in this post. But you can use any version from this link. - http://sourceforge.net/projects/gns-3/files/IOU%20VMs/
IOURC - Cisco license file for IOU Images. It is not available for public use, but while surfing I found this link which could help you! http://forum.gns3.net/topic9032.html