bri int in standby mode won't recognize serial line down

[tteslicko]

A bri int backup i am using in the UK defaults to standby mode with backup load commands. Works well with backup load thresholds, but won't come out of standby if administratively shut. What if the Serial line really goes down? Do I have backup? It seems to come up ironically has soon as I unshut the Serial 0/0 interface??

No biggie, but I was kind of hopeful from what i had heard on pretty good authority that if the Serial line went down, it was going to come out of Standby..I have scoured through the IOS to no avail.

[spremkumar]

hi

From my personal expereince when u shut the serial port the bri associated with it as a standby interface will not trigger out a call ,try doing switching of the modem connected to tht particular interface or pluggin out the serial interface cable tht will trigger out the call..

when u do like this the serial wont be admin down which will enable the bri to dial out ..

regds

[Kevin Dorrell]

Do you have backup interface as well as backup load? Could it be that backup load only applies if the original interface is up?

Kevin Dorrell

Luxembourg

[tteslicko]

yes..it is actually the "backup interface" command that seems to put the Bri Int in backup mode. Apparently there is difficulty in testing the backup this way as taking the Serial administratively down disables the administrative function of telling it about the backup int in , which is also administratively down (standby mode). Pulling the physical cable from the interface must be my next test or relying on the consensus of opinion on this site that it will in fact trigger the call if ever the signal is lost from the Provider.

[Richard Burts]

You have raised this question in two postings. As I responded in the other post, when an interface is defined as backup interface it is put into standby mode. It will not come out of standby mode if the primary interface is shutdown. The logic there is that if you shutdown the primary interface, that does not constitute a problem (you did it on purpose, so it does not constitute a problem) and the backup remains in standby. The only way to test the BEI is to produce a real problem on the primary -like disconnect the interface.

I can address part of your concern about whether you really have backup or not. I have experience in doing this and unless a serious bug creeps into the IOS, if the primary interface goes protocol down the backup interface will come out of standby and be ready to function. I have seen this work a number of times.

The other part of your concern about whether you really have backup should be the question of whether the BRI will work correctly when you need it. To address this I suggest that you need to periodically test the BRI and make sure that it really does work.

HTH

Rick

[jduffek]

You can't test the "backup interface" function by doing a "shutdown" on the primary. When you shutdown that primary you null the "backup" commands.

Pull the cable or shutdown the other end.

Josh