How to distribute traffic?

[anilsiri]

Hi,

I have a network with 512K dedicated circuit on fiber to LA, 256K dedicated ciruit on satellite to NYC and 1Mb shared internet on fiber. 512K and Internet circuits are on 2620 router and 256K ckt on 2500 router. I'm running OSPF on both the routers and HSRP to make 2620 the active router.
I have a default route to Internet. So if 512K ckt goes down the traffic goes through 256K ckt (this is because the LA and NYC offices are in turn connected and routers in LA and NYC participate in OSPF with my routers). As of now I'm able to use 512K and 256K ckt is completely acting as backup with no data on it. My intension is to put some data on it so that the load can be shared and redundancy does not break. Can you suggest some plan?

Anil

 

[routerman]

Interesting one, the servers on your LAN, can they run OSPF?

Currently the situation is, your server sends data to HSRP address, this router then looks in it route table, sees LA and NYC via the 512k circuit. This is normal operation, you still have redundancy, if the 512k link fails OSPF will reconverge to use the 256k. Presumably you have tested this at some time, is this what happens with the present setup?


If your servers at the core site can run OSPF then you could get them to receive updates from the 2 routers, traffic for NYC would then go via the 256k link, as long as OSPF advertised that as the best path. You could influence this by increasing the metric on the LA to NYC link.

Try increasing the metric on the LA to NYC link, you should be able to get the 2500 to advertise the best path to NYC anyway, so NYC bound packets would go to the 2620, then be forwarded to the 2500, and down the 256k link.

 

[anilsiri]

Thanks. But the routers between LA and NYC run iBGP also.

 

[routerman]

That may not be a problem, why do you need iBGP there?

You can run OSPF across that link as well as iBGP, but it depends on the redistribution scheme.

 

[tbilan]

This may not be helpful but have you tried EIGRP? It supports unequal cost load balancing.

http://www.cisco.com/en/US/partner/tech/tk365/tk207/technologies_tech_note09186a008009437d.shtml

Tom Bilan
TJBA, Inc.
CCNP, CCDP, MCSE & CNE