Cisco Support Community
Showing results for 
Search instead for 
Did you mean: 

Welcome to Cisco Support Community. We would love to have your feedback.

For an introduction to the new site, click here. If you'd prefer to explore, try our test area to get started. And see here for current known issues.

New Member

ISDN Interface Active But Cannot Ping

I have a backup interface for my Frame Relay. After the frame relay down, the ISDN is up and completely active. But I cannot ping my BRI interface.

Can you all help me with this.


012_RO_01#sh ip route

Codes: C - connected, S - static, I - IGRP, R - RIP, M - mobile, B - BGP

D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area

N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2

E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP

i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, ia - IS-IS inter area

* - candidate default, U - per-user static route, o - ODR

P - periodic downloaded static route

Gateway of last resort is not set

C is directly connected, FastEthernet0/0

S [150/0] via is subnetted, 1 subnets

C is directly connected, Dialer2 is variably subnetted, 2 subnets, 2 masks

C is directly connected, Dialer1

C is directly connected, Dialer1



Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to, timeout is 2 seconds:


Success rate is 0 percent (0/5)

Thank YOu


Cisco Employee

Re: ISDN Interface Active But Cannot Ping

Need to know the following debug with running config to start troubleshooting

debug isdn q931

debug ppp nego

debug ppp authentication

debug dialer

term mon

Are you using dialer map or dialer profile? If you use dialer map, pl. make sure to have same exact username of receiving side router in the dialer map which was presented during authentication..Pl. post it with the running config as well..

New Member

Re: ISDN Interface Active But Cannot Ping


Check that have you " dailer list # protocol ip permit " check this command global configuration mode.

I think its works.