NTP might have been a bad example for the timing reasons. One thing to keep in mind with anycast is that unless there are problems the routes are fairly stable and depending on how many servers you deploy and what route visibility you have even different providers will often see the same location as the closest path in terms of BGP.
I believe pool.ntp.org employs anycast to some extent, but I'm not sure about that. SNTP seems to to have a discovery component designed to work well with anycast. RFC 7094 has a good summary of all this. In general, the consensus seems to be that anycast is better used for discovery services rather than services themselves. On Wed, Jun 17, 2015 at 5:12 PM, Chuck Church <chuckchu...@gmail.com> wrote: > ----Original Message----- > From: NANOG [mailto:nanog-boun...@nanog.org] On Behalf Of Ray Soucy > Sent: Wednesday, June 17, 2015 3:14 PM > To: Joe Hamelin > Cc: NANOG list > Subject: Re: Anycast provider for SMTP? > > > >As such, you typically only see it leveraged for simple services (e.g. > DNS, NTP). > > I've been thinking about this for NTP. Wouldn't you end up with constant > corrections with NTP and Anycast? Or is the assumption your anycasted NTP > hosts are all peers of each other and extremely close in time to one > another? That still wouldn't address the latency differences between the > different hosts. > > Chuck > > -- Ray Patrick Soucy Network Engineer University of Maine System T: 207-561-3526 F: 207-561-3531 MaineREN, Maine's Research and Education Network www.maineren.net
