IOS 15.1-4.M12a for 2811 and 2821

[sburnside]

Where can I get IOS 15.1-4.M12a for a 2811 and a 2821?

[Leo Laohoo]

If you know the exact filename of the file, use a web browser to find/search for any site hosting the file. 

Cisco no longer allows anyone to download End-of-Support files.  

[balaji.bandi]

Both the kits  are EOL, if you have partner access ask if they can have old saved files.

or google can help you get files