Hi we have a 3825 at our main office connecting to several branches over tunnels. We were experiencing some bad magic chunk errors on a previous version of code so upgraded to 12.4(21).
However since the upgrade one of the tunnels drops out and re-establishes all the time. All other tunnels are fine except this one
Nothing has changed at the remote end, it's a 2821 router running 12.4-(13r)T
Is there some compatability issue here?
Nothing has changed in the config, so all I can think is it's this version of IOS but all other tunnels work fine
the only other difference is that the 2821 sits behind a NAT firewall all the others don't but this was never a problem before and it worked fine for 12 months