Brian,
I found the following in a Linux manual for the 'ip tunnel' command:
nopmtudisc -- disable Path MTU Discovery on this tunnel. It is
enabled by default. Note that fixed ttl is incompatible with this
option: tunnels with fixed ttl always make pmtu discovery.
If you create a tunnel that does not care about MTU state, it's also
unconcerend about the 'distance' the packet has traveled, your eth
interface would handle both tasks in that instance (being a 'dumb
tunnel,' if you will). With nopmtudisc on, your 44Router would properly
fragment the packet when transmitting on eth and sets the ttl on the
ARPA Internet, as opposed to AMPRnet. If this command worked before you
updated your IP utilities, it was probally due to the previous version
not being written true to RFC.
73,
Lynwood
KB3VWG