We have a Cisco 1710 router running IOS 12.2(15)T10 and a Cisco 831
router running IOS 12.2(13)ZH.
I have a IPSec site-to-site VPN set up between the two which until
recently has worked perfectly well.
Now, I can bring up the tunnel from the 1710 end (by pinging internal
interface to internal interface for example) but if I try initiating
this from the 831 end, the tunnel will not come up.
This seems to have been an issue roughly since I reloaded the 831 a
week ago but I saved the configs before doing it so I can't see that
any config will have changed.
Can anyone shed any light on what this might be? If you need more
info, I can provide it - just let me know - I look forward to your
responses - thank you in advance.