On Thu, Jul 15, 2010 at 6:15 PM, Robert Keyes <[email protected]> wrote: > > > On Wed, 14 Jul 2010, Bill Bogstad wrote: > >> >> While the above is technically correct, in his circumstance BGP is not >> an option. To do BGP you TYPICALLY need to >> own your IP address space in order to be able to advertise them >> successfully. He's talking about how many addresses his provider is >> going to give him so he doesn't have such addresses. > > Not really. You can get a chunk of IP space from your main provider, and > advertise a route to it through your backup provider. This is becoming more > common as IPv4 space is becoming a more expensive commodity.
In the past, providers would refuse to do this. Maybe it's changed. > >> Second, the address space he's talking about is so small that even if >> he does get addresses and providers who will do BGP, no one else will >> pay attention to his advertisements anyway. > > Yes, this is true, you generally need a /24 (a.k.a. class C, 255 IP > addresses) in order to be sure your route is propagated across the whole > net. But I am a bit unusure of this, there may be ways around this problem. > >> Each advertisement takes >> up expensive memory in core Internet routers and the larger network >> providers aren't going to spend lots of money so he can have redundant >> network providers. Don't go there. > > Well yes it does take up more memory, but that doesn't mean the route won't > propagate through BGP. I still regularly get route announcements for very > small allocations (as small as a single host!), and people won't announce or > propagate such routes if they didn't have value. If you are "very important" networks will allow smaller allocations through. I think some of the DNS root servers are using "anycast" and small BGP announcements for redundancy purposes. I still think this is likely to be a non-starter for someone in the original poster's situation. However, if he wants to pursue it; he could go look at the archives for the NANOG mailing list for what is typical practices on BGP announcements. Bill Bogstad _______________________________________________ bblisa mailing list [email protected] http://www.bblisa.org/mailman/listinfo/bblisa
