North American Network Operators Group
Date Prev | Date Next | Date Index | Thread Index | Author Index | Historical

Re: /8 end user assignment?

  • From: Joe Abley
  • Date: Fri Aug 05 09:56:34 2005 
On 5 Aug 2005, at 07:54, Sabri Berisha wrote:


On Fri, Aug 05, 2005 at 04:10:46AM -0700, Bill Woodcock wrote:

      On Fri, 5 Aug 2005, Sabri Berisha wrote:
With the use of anycast DNS servers on the internet, TCP is no longer an
option for DNS.
Bzzzt.  Try again.

			/--[cabernet]--[merlot]--[riesling]--[server 1]
[end-host] ----- [shiraz]		  |
			\--[sangria]]--[chardonnay]--[bordeaux]--[server 2]
It is of course possible to construct networks through which TCP behaves very poorly with anycasted services. This does not mean that TCP is fundamentally incompatible with anycast.

There are plenty of examples of people anycasting services which involve long-held TCP sessions (like FTP servers, and HTTP server serving large media files). Naturally not all networks and not all node placement decisions will work for these kinds of services, but it is certainly possible to use anycast to great effect with very high service quality.

See draft-grow-ietf-anycast-01 for more commentary.


Joe