route cache on machine if the gateway changes the route

t4tauseef33 · ‎03-19-2009

Hi,

I have setup in which all the machine gateway is one router R1 and that router has 2 other routers R2 & R3 to forward the request (Primary and secondary in case on router goes down). R1, R2 and R3 are in the same vlan in the same subnet. if R1's primary route is via R2, then the machines have the gateway for subnet via R2. if the R1 decides to go via R3, but the machines still got the R2 information in its routing table for 5 minutes. how can i setup that machines always go to R1 and will not get next hope R2 / R3 information from R1.

Edison Ortiz · ‎03-19-2009

Disable ip redirect on R1's client facing interface.

http://www.cisco.com/en/US/docs/ios/ipapp/command/reference/iap_i1.html#wp1053898

HTH,

__

Edison.

Joseph W. Doherty · ‎03-19-2009

If you only use R2 and R3 as primary/backup, you could use HSRP. Active gateway would be on R2, standby on R3.

You might also configure R2 and R3 with virtual gateways using MHSRP that backstop each other. This assumes you want to split the load to each.

PS:

Another choice is to use a dynamic routing protocol between the routers.

[edit]

PPS:

Rereading your post, I believe I provided a solution for the wrong issue, however the HSRP/MHSRP variation may also solve your client issue. The latter depends on whether R1 would provides host client redirected virtual gateways. (I think it does, but I'm not positive.)

Unless you really see the need to avoid client machines avoiding an unnecessary hop via R1, Edison's solution is the method of choice.