??Source Based IP Routing - Possible??

Unanswered Question
Dec 18th, 2002
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Greetings -

I have 4 boxes on the same subnet that are required to hit the same destination IP host address through two different WAN links.

One company bought another and we deal with both of them. The parent company wants all traffic to hit the same IP Host but they do not want to change their firewall rules to allow all traffic to go through a single WAN link.

So, the question is - is there any way to set up different routes to the same IP destination, based on the source IP of the box.



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vmiller Wed, 12/18/2002 - 12:26
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Take a look at route maps. I believe you can do things such as set next hop..

SGingolaski Wed, 12/18/2002 - 13:19
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Thank you for the reply VMiller.

If you are referring to Route Maps on the hosts themselves, the problem with that is that they need to go through the same core router to hit the WAN links.



vmiller Wed, 12/18/2002 - 14:50
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I think it would take 2 (or more) steps.

on the router that the hosts are connected to, set up access lists to inspect each host address and set a tag on the packet.

on the wan routers, set up route maps to:

1. inspect the tag set above

2. forward to the proper interface based on tag.


vcjones Wed, 12/18/2002 - 14:58
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What you are looking for is called policy routing and on Cisco boxes it it implemented using route maps to define the policies and ip policy route-map statements on the interfaces the packets to be policy routed come in on. See http://www.cisco.com/warp/public/105/36.html for an explanation and example.

Good luck and have fun!

Vincent C Jones



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