dectect link down

[pccthailand]

hello all

I used isdn for backup primary link when i want to test my isdn, i release primary interface and then it will dial-out but the last week my primary link down and Line Protocol change state to DOWN (Interface still UP),my isdn didn't dial-out . I checked my DDR Routing and Layer 1,2 isdn , it's ok!!

how can i do this situation ?

[Georg Pauwen]

Hello,

you might want to use a tunnel with keepalives for tracking purposes, which IOS version are you running ? If you post the configurations of both your routers, I can add the tunnel configs. The idea is that the tunnel status, rather than the status of the serial interface, triggers the ISDN backup...

Regards,

GP

[Richard Burts]

While I believe that Georg's suggestion about changing the config to use tunnels is an interesting one and would improve things, I believe that the original post shows that there may be a problem that we need to understand. If I understand the original post correctly Tawee has configured the isdn as a backup to the serial interface. There was a situation where the serial interface went protocol down but the isdn did not dial as it should have. Would Tawee post the config of the router with the backup interface and also post any output he may have from the time of the problem (I would especially hope to see output of show interface showing the seerial with protocol down and see any status of the isdn showing that it was in a normal state. any other output may be helpful).

HTH

Rick