best practives multi-homed BGP 2 physical locations

Is there any best practices documentation on how to run BGP multihoming accross two phyiscally seperated sites.

I found the following helpful, presented by Philip Smith at NANOG 41


Does this include Multi Site + Multi Homed

Easy part:
I need to provide my users acces to the internet from my HQ site via a local Internet connection or via a colo.

Hard part:
I also need to provide incoming access to hosted apps (HTTP, FTP, SMTP) from either location, so if the colo internet connection goes down the traffic can re-route to the HQ server farm and visa versa.
I am in the process of purchasing an AS and ip space. Is it advisable to use the same IP space at both locations and run iBGP over a dedicated L2 connection between the sites.


so, say you end up with a /24 and your ASN

split up your /24 into hq-/25 and colo-/25

from colo:
1) announce /24 as a standard adv
2) announce colo-/25 with *no-export* community set

from hq:
1) announce /24 as a standard adv
2) announce hq-/25 with *no-export* community set

Run iBGP over a dedicated link b/w colo and hq (I don't like allow-as in! but it is another option)


I'm fortunate to have a /16, and advertise 2 /18s from the primary, and 4
/17s from the backup collo, /16 from both with AS Prepend on backup /16,
and depend on BGP longest prefix route selection to create symmetric
Internet routing back to my locations. I run IBGP between geographically
diverse locations internally, over an L2 VLAN extended over a GiGE dot1q
trunk. Internet-facing load-balancers select the best server from
distributed server farms spread across the 2 sites.
I think this is a fairly standard configuration.