> I think they know better than to try to flap BGP routing > around to accomodate a failed computer at one site or > another, though. Is that what you are suggesting? > > BGP would normally be used to handle routing over multiple > paths to a fixed location and would change in response to > the route availability. You can play tricks by shuffling > a route to a completely new destination if a whole site fails > but the minimum you could move would be a whole class > C at a time, and some bad things will happen during the > switch as different machines with the old IP's become visible. I'd venture to guess that Google's public IP's have absolutely nothing to do with their internal IP's, with the machine you actually reach being probably based on some hash function of your IP, your country, location, ISP, the time, the currently working google-servers, load on the servers, etc. With all this NAT happening on the edge of their network space. Very, very difficult to set up correctly, but once it's working it's VERY powerful. Add on to this BGP changing when entire data-centers fail with possible help from DNS updates and you have a pretty robust system. Cheers, MaZe.