unreachability tracking

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Mar 24th, 2009
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I want to activate the backup route only when the normal route is not reachable. (using the priority doesn't work in my case because some traffic mount the bri even if it have lower priority)

I played with the track command but I can just deactivate the route when it is not reachable, I want to do the opposite aಐctivate a route on a non-reachability.

See attached network-diagram


- we are using a cisco 1712 to establish a VPN to a SonicWall at our MainOffice

- in case of internet communication failure we want to mount an ISDN connection to the ISP cisco router (the sonicwall doesn't have bri interface) to reestablish the VPN to the public ip of the SonicWall.

- Using the priority on the ip route doesn't work as some ip traffic intermitenly bring the bri up.



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lamav Tue, 03/24/2009 - 08:30
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Please post the complete configs of your router.

Remember, that simply adjusting the AD may not be enough. The static routes have to have comparable prefix lengths.

By the way, when you say "priority" of the route, I am assuming you're talking about the Administrative Distance.

You also have to set the interesting traffic access list on your ISDN connection.

lamav Tue, 03/24/2009 - 13:28
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Youve sanitized your config so much that to a certain extent it makes it a bit more difficult to help you.

Anyway, I see this route:

ip route Dialer1

with no comparable and better route over the primary link.

Are you sure traffic destined for that network is not bringing the ISDN link up?

What about router generated traffic, like SNMP?

You may have to run a debug on the ISDN connection to see which traffic is bringing it up.

Also, go into your routing table while the primary link is up and make sure that no route exists in it that has the dialer as a next hop.

jrlaroche Thu, 03/26/2009 - 11:54
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The 192 route is the next hop of the isdn on RTR2.

concerning the traffic I've deactivate snmp etc and still have the link getting up

Wed Mar 25 17:41:37 2009: <190>47: *Mar 25 15:23:44.030: %DIALER-6-BIND: Interface BR0:1 bound to profile Di1

Wed Mar 25 17:41:38 2009: <187>48: *Mar 25 15:23:44.034: %LINK-3-UPDOWN: Interface BRI0:1, changed state to up

Wed Mar 25 17:41:40 2009: <189>49: *Mar 25 15:23:46.434: %LINEPROTO-5-UPDOWN: Line protocol on Interface BRI0:1, changed state to up

Beside other aspect Is it possible to track a route on unreachability??



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