Here is a configuration from my 2600.
The config on your 2500 should be simular, but the line # will be different. If you look at the ip host line, the socket is 2000 + the line #, which starts at 33 on the 2600. Also notice transport input all in the line config.
Doug
!
!
ip subnet-zero
ip tcp synwait-time 5
no ip domain-lookup
ip host cat 2039 150.100.7.7
ip host r6 2038 150.100.7.7
ip host r5 2037 150.100.7.7
ip host r1 2033 150.100.7.7
ip host r2 2034 150.100.7.7
ip host r3 2035 150.100.7.7
ip host r4 2036 150.100.7.7
ip host tr1 2040 150.100.7.7
!
!
!
!
interface Loopback0
ip address 150.100.7.7 255.255.255.0
no ip directed-broadcast
!
!
line con 0
exec-timeout 0 0
privilege level 15
transport input none
line 33 48
no exec
transport input all
line aux 0
exec-timeout 0 0
privilege level 15
