I have an X.25 over ISDN configuration which running on a 1721 router. I can telnet from a host to port 1998/tcp (XOT) on the router.
This configuration is to be migrated to an 876 router, but I am unable to connect to the XOT port with the same configuration. I have tried the latest rebuilds of 12.4(15)T, 12.4(11)T and 12.4(9)T - all Advanced Enterprise feature set. The 1721 uses a 12.3 IP Base feature set.
Is there anything which needs to be enabled to allow connection to port 1998/tcp (XOT)?