[c-nsp] Cisco IPSec VPN's (Tunnel Interfaces) migrating from 12.2.25 to 15.1.4

[A.L.M.Buxey at lboro.ac.uk]

Hi,

> I'd be surprised if something didn't migrate over automatically.  IOS will
> accept older style commands, and upon parsing them, changed them to the new
> format itself.  You sure you're not running 12.4(25)?  I don't think 2800s

if the configuration format is deprecated then you can get the new format
sometimes updated for you...generally though you will get a warning and the old
config method is written - and will still work... but the warning should serve
as time to upgrade your configuration - thinking of RADIUS and TACACS+ config
layouts on 15.x upgrades that I've seen. if the config method is no longer deprecated
and is now obsolete then yes, you may have issues - the software engineers are
going to keep backwards config parsing/compatibility only for some time.

alan