Multihome through same carrier, load balancing?

[tahscolony]

We have two sites separated by dark fiber, each site has an internet connection with the same ISP, with same IP addressing in an active standby setup. We will be increasing bandwidth at each site, have our own ASN and IP space now, and would like to be able to use both circuits for load balancing. Behind each router are duplicate routers and firewalls, the routers use unique IP's, the firewalls in an active/standby configuration.

If we lose internet at the main site, iBGP kicks the default over to the other building. What I am looking to do is to be able to pull the full BGP table, and let each router determine best path, but being that both are from the same carrier, granted each link is out of a different office, possibly out of different routers as well, would there be any difference in paths for shorter paths?  At some point we may get a 3rd carrier to do true multihoming with, but for now there is only one provider with the bandwidth.

[Mark Malone · Accepted solution]

Hi

if I understood that right there is a way to LB when you have one provider with 2 links, see the section below in the link for an example  

http://www.cisco.com/c/en/us/support/docs/ip/border-gateway-protocol-bgp/13762-40.html#anc15

Load Sharing When Dual-Homed to One ISP Through Multiple Local Routers

[tahscolony]

perfect, that's what I was searching for.  I hate having a 500 Mb circuit sitting idle when there is always some way to put it to use.

[Mark Malone]

Ah that's good , yes your right wan circuits are 2 expensive to be sitting there doing nothing