Redundant path for inbound traffic to static IPS on different ISPs

[angel-moon]

Hello All,

I am looking at trying to configure load sharing for a customer across 2 different ISPs on 1 router. I know that I can use GLBP for the outbound traffic but and having a problem with the inbound.

Both connections have public static IPs assigned from the ISP. I want to be able to reach ISP A's static IPs through ISP B's ISP whenever ISP A's connection is down and vice versa. There are not T1s. They are cable and DSL. lines. I believe this can be achieved by getting an AS number and running BGP but I am also told that each ISPs would have to agree to advertise the other ISPs IP range.

Can someone tell me if I have to involve the ISPs? I have found products (Fatpipe, etc.) that seem to say they can handle the inbound traffic in just this manner. If that is true then it would seem that I could do the same with a Cisco router.

Thanks in advance! All replies rated!

Angel

[Giuseppe Larosa]

Hello Angel,

>> I want to be able to reach ISP A's static IPs through ISP B's ISP whenever ISP A's connection is down and vice versa. There are not T1s. They are cable and DSL. lines. I believe this can be achieved by getting an AS number and running BGP but I am also told that each ISPs would have to agree to advertise the other ISPs IP range.

My suggestion is to go for enterprise multihoming with NAT.

When the link of ISPA is down you need to use ISPB.

>> I want to be able to reach ISP A's static IPs through ISP B's ISP whenever ISP A's connection is down and vice versa.

This cannot be achieved without an explicit agreement between you and the two providers: without it you will end up on ISPA on some waste bin (null0) when ISPA link is down

see for enterprise multihoming with NAT

http://www.cisco.com/en/US/tech/tk648/tk361/technologies_white_paper09186a0080091c8a.shtml

Hope to help

Giuseppe

[angel-moon]

Thanks Giuseppe!

[sudhir.bhagat]

Hii Angel,

Agree with Giuseppe , for proposed scenrio to be working you need to involve both ISPs.

@ Su.Bh