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dial backup using ISDN

Hi all

I wand to configure backup interface by using ISDN due to i don't want to the backup going up without looking to the routing table i just want to look to the interface i try to but it didn't work so i want to know the configuration and ask if i can do something that make the backup going up if it found the quality of the line it not working will


notes. using EIGRP . Iam star think of that due to every time i do H2H connection i must enable the EIGRP on the remore site and some does not working with EIGRP so iam going in this direction .if u have something can solve this problem by anther solution let me know

VIP Purple

Re: dial backup using ISDN


there is a feature called Link Quality Monitoring, which allows you to set a treshhold value: in case the link quality percentage is not maintained, the link is deemed to be of poor quality and is taken down.

Here is an example config:

interface serial 2

backup interface bri0

encapsulation ppp

ppp quality 80

In this example, if the quality of the link falls below 80%, the line is taken down and the backup line (BRI0 in this case) will come up.

Check this link for the syntax of the command:



Community Member

Re: dial backup using ISDN

Dear gpauwen

the quality command is useful but i still have the problem with the backup int i mean to configure it.i read configurating dial backup for serial lines with example and i try to do it but it didn't work so i will be greatful if u can inform me where i can find scenatio due to i still don't know why it didn't work


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