Hello Zaman
On the left you will see a yellow star indicating which release Cisco suggests is the best for you to download. This is based on a balance between which one is currently the most stable, has the most bug fixes, and has the most new features and platform support. Choosing the “yellow starred” release is always best, unless you are looking for a particular IOS for some reason.
Now notice there there are MD and ED releases. According to Cisco, this is the meaning of these release types:
- Early Deployment (ED): These releases provide both new features and new platform support in addition to bug fixes. These have an 18 month support window.
- Maintenance Deployment (MD): These releases are used to provide additional support for bug fixes and ongoing software maintenance. These have a 44 month support window.
Your original IOS version was an ED release, which you can see from the E in the name:
“cat4500e-universal.SPA.03.06.00.E.152-2.E.bin”
Now having chosen the specific release, you see several download options. You have universal images, and a crypto images. The crypto images are capable of enabling “strong cryptographic features” for use with SSH, HTTPs, IPSec etc… The universal images do not support these. Why? This is due to certain laws that prohibit the export from the United States of products with strong cryptographic features to certain countries, such as North Korea. Always choose the crypto images if you are in a country that allows them.
Finally, you have the choice of downloading a tar file or a bin file. Cisco describes it as follows:
The .bin file is the Cisco IOS Software image. If you want to use only the CLI to manage the switch, this is the only file you need to download.
The .tar file is an archive file from which both the IOS image and the CMS files are extracted during the upgrade process. If you want to manage switches or clusters of switches through a web interface (HTML), this is the only file you need to download.
For your purposes, only the bin file is required.
So you should download the Universal Crypto image bin file, or cat4500e-universalk9.SPA.03.11.02.E.152-7.E2.bin.
I hope this has been helpful!
Laz