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Route shaping / Route Mapping

Ok I am looking for a way to propoerly force specific traffic over a specific link. I am thinking that I need to dp this with route mapping but am not sure of this is handled by the core or by the edge routers.

Here is the senario. I have two links connected to two different routers and both routers are inturn connected to the same core switch. Link #1 is a 3M serial link and link #2 a 10M Ethernet link. The router supporting the 3M link is a 3825 and the router supporting the 10M link is a 2921. The switch they are connected to is a 3750G.

We have installed two SANs within the network and one is located at the facility supported by these two links. They have started replication between the two SANS and I want to prevent this replication traffic from flowing over the 3M. If the 10M goes down for any reason the replication will be paused or stored until the link comes back up. What do I need to do to advertise / route the traffic between the two SANs over the 10M link? I use EIGRP between the core and the two routers and use BGP between the two routers and my provider. I am thinking the end goal is to not advertise the VLAN the local SAN is attached to over the router with the 3M link attached. Since both routers use the same EIGRP instance if there would be some massaging on both routers or do something unique on the core.

Where do I start? I am working on a refrigerator diagram that shows how things are interconnected and will attach shortly.


Thanks in advancce...


Everyone's tags (4)

Hi, In EIGRP, you can use



In EIGRP, you can use offset-list to choose the preffered path to go with for a certain host or certain source subnet. You can learn and check if you can tweak it to make use in your scenario.




Hi Brent, Just make sure the

Hi Brent,


Just make sure the the core has a better metric path to reach the other SAN subnet via the 10M link, Do you want to use the 3 M link as backup - if so the core must see the 3M link is a feasible successor.

You may need to check that the cores at both ends agree on the 10M link as the path between the 2 SANs.






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