North American Network Operators Group Date Prev | Date Next | Date Index | Thread Index | Author Index | Historical Re: bad idea?
On Wed, Jul 05, 2000, Greene, Dylan wrote: > > > Jeremiah, > > Hey there.. What you're describing is basically anycast, (rfc 1546) which is > useful for single packet, connectionless UDP type things (dns lookups), but > can make connection oriented / statefull protocols break. > > If you are advertising what appears to be two ways to get to the same > prefix, you're relying on having stable paths through the internet to always > deliver a packet via the same path the one before it took. If something > outside of your control breaks / changes, you may end up changing paths and > could start sending packets towards your 'other' (same destination) site mid > session. > > Another thing to be careful of is inconsistent-as. If you plan to have > multiple sites advertising the same prefix, they either need to be all part > of the same asn, or you need to advertise a separate anycast asn padded w/ > unique per-site asns. (Also a good way to withdraw routes is necessary, > using gated or something..) > > I think the anycast rfc mentioned setting aside a block of space for this > purpose. If you originate it from the same AS then yes, it works just fine. I've run it for web servers before, without a complaint, and a few people here have run it for streaming media and can give you feedback. I haven't tested it for long-held streaming media connections so I can't comment. Adrian
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