Does BIND9 support broadcast/multicast query?

[Mark Andrews]

> Hideshi Enokihara wrote:
> > Thank you for your reply.
> > 
> > On Mon, 26 Dec 2005 09:58:54 -0800 (PST)
> > Gregory Hicks <ghicks at cadence.com> wrote:
> > 
> > 
> >>>Date: Mon, 26 Dec 2005 19:30:23 +0900
> >>>From: Hideshi Enokihara <Hideshi.Enokihara at jp.yokogawa.com>
> >>>To: bind-users at isc.org
> >>>Subject: Does BIND9  support broadcast/multicast query?
> >>>
> >>>Hi all,
> >>>
> >>>I have a simple question for BIND9.
> >>>
> >>>Does BIND9 support a UDP query that is delivered using an IP
> >>>broadcast or multicast address?
> >>
> >>broadcast/multicast is handled by the router long before the request
> >>ever reaches the server.  As far as the SERVER is concerned, it just
> >>sees a request and processes normally.
> > 
> > 
> > I see.
> > But RFC1123 says,
> > 
> >             A server MAY support a UDP query that is delivered using an
> >             IP broadcast or multicast address.  However, the Recursion s
> >             Desired bit MUST NOT be set in a query that is multicast,
> >             and MUST be ignored by name servers receiving queries via a
> >             broadcast or multicast address. 
> > 
> > So, I think that sarver may support a broadcast or multicast query, Not rou
> ter.
> > How do you think?
> > 
> The only part of RFC 1123 that is relevant to this question as far as I
> could see was Section 6.1.3.2 where the discussion at the end of the
> section discourages broadcast and multicast for finding name servers.
> I don't remember seeing RFC's suggesting that nameservers support
> broadcast or multicast for anything.
> 
> Danny


	BIND 9 does not support multicast queries.  It does not
	have code to join a multicast group so it will never recieve
	multicast queries.

	As for broadcast queries it will respond to them however there
	is no code in the resolver to special case that the source
	address of the reply won't match the address the query was
	sent to.

	Mark
--
Mark Andrews, ISC
1 Seymour St., Dundas Valley, NSW 2117, Australia
PHONE: +61 2 9871 4742                 INTERNET: Mark_Andrews at isc.org