I have a Cisco Router 871 with base IOS image. I need to upgrade the IOS to advanced security, because a need configure some vpn L2L tunnels.
One of my friends give me the IOS image (c870-advsecurityk9-mz.124-22.T.bin) he download it from one of him routers. I know that i can change the image and maybe the router could be work fine, but i think this is not the legal way.
¿How can i do the upgrade in correct terms?
¿exist a part number to do it?
Regards,
PD: Sorry for my bad english.