Re: DNS problem (forwarding order?)

[Thomas Hood <jdthood aglu demon nl>]

David MacMahon wrote:

> Dan Williams wrote:
>
> > So it appears to say in the RFC (2132) that the servers should be
> > contacted in order returned from the DHCP server.  How do we tell bind
> > that's how we want it to work?
>
> I don't know whether bind has an option to always query the forwarders 
> in the order given.
>
> A possible alternative would be run bind listening on MAXNS (3 on FC4) 
> ports with each port's server having only one forwarder.  Then 
> resolv.conf could contain MAXNS nameserver entries; one for each of 
> the different ports.  The "only" hitch is that the man page for 
> resolv.conf (on FC4) doesn't mention anything about how to use 
> different ports in resolv.conf.

Here is a good reason, then, to use dnsmasq rather than bind.
When dnsmasq is run with the --strict-order option it always
consults nameservers in the specified order.  (Its default
behavior is to try to be smart: Start with no current server,
in this state queries are sent in parallel to all servers. The
first one to reply becomes the current server. Subsequent
queries are sent to that server alone. If a query to the
current server times out without a reply, revert to the
initial state and retransmit to all in parallel, select a ne
current server based on who wins the race.)

Another reason: the dnsmasq package in Debian is one third the size of 
the bind9 package.

Another reason: dnsmasq is designed from the ground up as a caching 
nameserver.

Another reason: dnsmasq does not need to be restarted or
even signalled when the list of nameservers chagnes.  dnsmasq
can be configured to poll a file which lists the nameservers it
should use.

Another reason: If dnsmasq is used then there is no need for it
to be run as NM's private instance.  dnsmasq naturally coexists
with bind running as an authoritative nameserver.

There may be reasons for preferring bind but if they were
mentioned then that was before I joined the list.  Hopefully
someone will clue me in if that is the case.
--
Thomas Hood