Anycast

[David W. Hankins]

On Thu, Sep 04, 2008 at 07:40:22PM -0400, Jeffrey Hutzelman wrote:
> --On Thursday, September 04, 2008 10:00:49 AM -0600 Jerimiah Cole 
> <jcole at tbtc.net> wrote:
>
>> Has anybody considered using anycast for moving requests from relay
>> agents to servers, or is the behavior of most relay agents such that
>> this is unnecessary?
>
> That's an interesting idea, but we've found it unnecessary.  The relay 
> agents in our cisco gear forward the requests to all configured server at 
> once, so every server sees every request at the same time, and there's no 
> delay if one of the servers is down.

Ditto.  DHCP packets are small and, between relay and server, unicast.
No big thing to hit all servers and use something like LBA.

I missed this original message (or maybe I thought it was DNS related,
sorry about that).

I do think that someone (maybe on the old dhcp-server list?) did
report they were using an anycast setup with ISC DHCP, switching to
BSD sockets (so not using any raw sockets) and using some, at that
time, undocumented options to bind to specific addresses.

I don't know how (or if) that panned out.  Usually we hear when things
break, not so much when they work.

-- 
Ash bugud-gul durbatuluk agh burzum-ishi krimpatul.
Why settle for the lesser evil?	 https://secure.isc.org/store/t-shirt/
-- 
David W. Hankins	"If you don't do it right the first time,
Software Engineer		     you'll just have to do it again."
Internet Systems Consortium, Inc.		-- Jack T. Hankins