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ISDN Problem


i have a leased line and isdn.

leased line is up and working using ospf .my isdn is configured using static root with higher AD

configuration is ok as this same configuration is on another router other problem is that inspite leased line is up my isdn always remains active dialing out.

what could be the problem how can i stop isdn from dialing .

configuration attached .




Re: ISDN Problem

HI Ash,

There can be few reasons as per your config why isdn is coming up although the lease line is up.

First your dialer list allows all the ip if you see in your config which means even the ospf hello packet can trigger the isdn.

You can use "sh dialer" command to find out the source and destination ip which is triggering the isdn.

Also if request to destination in 10.x.x.x subnet which is not available in your routing table it will trigger the isdn.

Because the isdn and lease line are on same router the best way to overcome this problem will be to configure backup interface. Which means the backup interface which is isdn interface will only come up when the primary interface which should be your lease line goes down.

Just have a look at this link for confioguring backup inteterface

Should look something like this

interface serial 0

backup interface dialer 1

backup delay 5 10

HTH, if yes please rate the post.