EIGRP used for outside use?

[jjoseph01]

Can you use EIGRP for external use? I have a situation where I have two ISPs. I want to use EIGRP for load balancing purposes. I have this situation: LAN --> Firewall --> Cisco router --> then TWO Cisco routers to two different ISPs. Im not sure really how to go about using it for two ISPs. I want load sharing, but not sure how traffic will route out. Any ideas on how to do that? Or if you can point me to a document that spells that out, that would help to. I have looked quite a bit for one without success. Thanks.

[rais]

Given you have ISPs and FWs, it would be better to use BGP.

Thanks.

[sourabhagarwal]

you can't use EIGRP with ISP as EIGRP is interior gateway routing protocol which can run only in a single autonomous systems (AS) and not between AS.

you need to run BGP, if you want your AS to communicate with external AS (ISP), as BGP is exterior routing protocol which will run between different AS.

check this URL which explain to configure load balance with BGP which I think fit with your scenario.

http://www.cisco.com/warp/public/459/40.html#conf5

hope to help ... rate if it does ....

[jjoseph01]

Even if the two ISP routers are onsite at the customer, I cant use EIGRP? I was thinking if I could get the ISP to configure EIGRP on their routers, which sit on the customer site, I would be able to use EIGRP with the one router behind the two ISP routers. Is that not correct?

[Richard Burts]

I take a different approach in this than Sourabh. I would make a distinction between what you "could" do and what you "should" do. You "could" run EIGRP - if the providers agree to do this, and I think this is a very BIG if. The functioning of AS in EIGRP is significantly different than it is in BGP and you could declare an AS on your router and if the provider declared the same AS then you could exchange routes. It is a matter of some speculation what routes the provider would inject into its EIGRP and whether that would really be beneficial to you. But it COULD be done.

As the other posts have pointed out - when you are dealing with 2 providers what you SHOULD do is to run BGP.

HTH

Rick