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Redirected Traffic, multiple routers & paths- VERY CHALLENGING QUESTION!!!

Unanswered Question
Dec 19th, 2003
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We have two routers at a site (for redundancy) and two links back to the main location. The primary link is a PTP Full T1 and the secondary link is slower link used for backup.

The customer would like to utilize the secondary link for HTTP when both links are up. The trick is they would like for all traffic to flow across one link if either the primary or secondary link fails.

So given normal conditions, a route map is utilized to redirect traffic to the secondary router with the slower link. When the primary link fails, all traffic flows over the secondary link. If the secondary link fails, HTTP traffic is sent to the secondary router and dropped because the link is down. The primary router has the route map for that redirect and does not know that the link is down on the other router. Thus secondary router receives the packets and drops them.

Is there a way for the primary router to "monitor" the status of the link on the secondary routers sync port?

Does anyone have any ideas on how to accomplish this goal?

I thank you in advance for your aid.

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kkalaycioglu Fri, 12/19/2003 - 06:46
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Are you using HSRP to provide default gateway redundancy for your outbound LAN traffic ?

tbaranski Fri, 12/19/2003 - 18:04
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A new PBR tracking feature introduced in 12.3(4) may be of interest to you. It essentially allows for ping-based PBR. In your case, you could tell the primary router to only policy route port 80 traffic if the secondary router's next-hop (i.e., its adjacent router at the main site) is reachable via ping. See http://www.cisco.com/en/US/products/sw/iosswrel/ps5207/products_feature_guide09186a00801d1e95.html


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