User`s guide

Configuring
3-51
Scenario 2: Stations across a Source Route only bridge
Problem:
Assume station C has already communicated and the ATX has
learned the RIF associated with it. If station C has a MTU of
anything larger than 4500 and wants to transfer a file to station D,
it will not work.
Reason:
The ATX does have the Routing Control field to tell station C that it
can’t handle a 4500 frame size but the default for the ATX is 8144.
Solution:
Configure the dot1dSrPortLargestFrame OID with 4472, 2052 or
1470 depending on the MTU of the end station and the transport
(i.e., FDDI, Ethernet or Fast Ethernet).