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New Member

1 link in multilink has low reliability


2 256Kbps LL links bundle into 1 ppp multilink between 2 sites.

The problem come into the picture when 1 link got reliability less than 255.

Packet keep sending to both links and ofcourse some didn't reach destination which cause application error.

Now I have to shutdown that link to solve this problem while waiting for carrier fix the problem.

Can I configure router to drop the low reliability link off from multilink automatically?

It takes time to find out this problem so it should be better to let router solve this at first.

Best Regards,



Re: 1 link in multilink has low reliability


I am afraid that the only viable solution is to shut the buggy link down manually. It will only drop from the bundle if it is totally gone, that will be far too late for your applications.




Re: 1 link in multilink has low reliability

There is a link quality monitoring mechanism available in IOS. It implements PPP Link Quality Monitoring as specified in RFC1989. You can try it, but it may or may not substantially help you in a leased-line situation. The problem is that LQM will tear down the link if it's unreliable, but because it's a leased line, it will come right back (if line conditions permit completion of LCP/IPCP).

You _should_ be able to combine this with the new IP Event Damping feature to hold down the link for a while if LQM fails the link several times. I have not tested this configuration, and I would recommend you consult TAC if you want to try it. Here is more information:

New Member

Re: 1 link in multilink has low reliability


There is feature called as "PPP multilink minimum links mandatory" which if combined with PPP LQM will help you resolve your issue

LQM will take care of the erred links in the bundle by bringing them down & the new feature will take care of the bundle interface by bringing it down if there are not sufficient links in the bundle itself

Hope this helps