Fix “This device isn’t eligible for the requested build”

I have iPad 2(GSM) version. It was on iOS v 5.1.1 firmware, yesterday I finally made up my mind to upgrade it to iOS 6.1. iTunes downloaded some 800 MB firmware and when it begin to load into iPad it gave the following error.

“The iPad could not be restored. This device isn’t eligible for the requested build”. Its pretty annoying when it takes nearly 1.5 hours for just firmware download. I looked up in google for solution but found only one working solution.

Here is the solution

Advanced: Manually Editing Hosts

Quit out of iTunes
Go to the hosts file. For Mac OS X this is located at: /etc/hosts or /private/etc/hosts and in Windows it is located at: c:\windows\system32\drivers\etc\hosts
Open the hosts file with Administrative privileges so that changes can be made and saved (eg: sudo nano /etc/hosts)
Look for a line that resembles something like this:
74.208.10.249 gs.apple.com

Put a # in front of that to comment it out, making it now look like this:
# 74.208.10.249 gs.apple.com

Save the hosts file
Flush DNS cache using terminal

dscacheutil -flushcache

and restart iTunes

Thank to oxdaily website’s tutorial on this fix.

As soon as I again tried it perfectly restored, now finally I am on ios 6.1.