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ISDN Backup with ethernet interface

Hi evrybody,

we have a router with one ethernet interface and one ISDN BRI port.

Wireless Broadband link(primary link) is terminated on ethernet interface.And Backup ISDN(secondary link) is terminated on ISDN BRI port.The problem is that when destination network is not reachable via primary link it should fire backup ISDN,but it doesnot happen bcos primary route is always there in routing table due to "ethernet is up,line protocol is up".

Kindly suugest.Early response would be apprciated.


Re: ISDN Backup with ethernet interface

That is a concern yes. The best way to overcome this is to run a routing protocol so even if the ethernet is up the updates will fail. or another solution would be to use object based tracking. Keep tracking a remote object and attach the track with your route. If the link is down, the tracking fails and you are up and working on secondary

Re: ISDN Backup with ethernet interface


As the other poster mentioned you can use either Object tracking feature or run a routing protocol between the site and remove the route from the table once theres some failure in the ethernet link.

for more info in object tracking do find this link..

one more suggestion is you can 2 GRE tunnels configured one over ethernet and the other one over the dialer.

route the traffic with some admin distance over the back tunnel configured over the dialer and keep the primary tunnl over ethernet to carry all the traffic by default.

do remember in this case u need to have keepalives enabled under the gre interface to sense and make the primary tunnel down in case of any probs with the connectivity..


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