nanog mailing list archives

Re: Anycast provider for SMTP?


From: Ray Soucy <rps () maine edu>
Date: Wed, 17 Jun 2015 17:38:10 -0400

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 <chuckchurch () gmail com> wrote:

----Original Message-----
From: NANOG [mailto:nanog-bounces () 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


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