I have Cisco 2520 and two remote locations. I set up two dial-in's: one isdn modem connected to port Serial3, and one isdn line connected to bri0. Problem: I configure both ports almost same, but connection to Serial3 works fine, Bri0 not.
Third-party router dial in (to Bri0), connect, ppp authentication - ok and then - the end. The connection stay alive but traffic don't pass, ping to remote loc. doesn't work.
Here is IOS:
version 11.2
isdn switch-type basic-net3
!
interface Ethernet0
!
interface Serial0
!
interface Serial1
!
interface Serial2
physical-layer async
ip address 192.168.50.1 255.255.255.0
no ip directed-broadcast
ip tcp header-compression passive
encapsulation ppp
keepalive 10
async default routing
async mode dedicated
no peer default ip address
no cdp enable
!
interface BRI0
ip address 192.168.10.1 255.255.255.0
no ip directed-broadcast
no ip mroute-cache
encapsulation ppp
no ip route-cache
isdn answer1 370
isdn answer2 370
no peer default ip address
no fair-queue
no cdp enable
ppp authentication chap
!
no ip classless
ip route 0.0.0.0 0.0.0.0 10.1.1.2
ip route 192.168.11.0 255.255.255.0 BRI0
ip route 192.168.51.0 255.255.255.0 Serial2