What can go wrong when migrating a Cisco 2911 configuration?

Question

Computer networks

Good afternoon, colleagues.
Please tell me, there are two Cisco 2911.
It was necessary to replace one machine with another, completely identical. Cleaned up the starting configuration (erase'om).
Filled in a config from the old machine. I checked the compliance and replaced it with a light soul. And surprised!
I go to a new tsiska from LAN (sees everything, enters) I ping 8.8.8.8 (Succes)
I ping 8.8.8.8 from the local machine, there is no ping. But IpSec sees everything from the local machine, but not from the cisco.
DNS, DHCP is a separate machine, on the tsiska, except for ACL, IpSec, there is actually nothing, even vlans did not bother.
I began to think that I missed somewhere a hidden setting that is not displayed in the backup (for example, there is no shutdown, which "turns on" ports)
Once again I repeat all night I checked the identity of the config: one to one.
Where could I be mistaken, not to take into account what?

Answer 1

Identity of software versions