DNS query timeouts
Farid Hamjavar
hamjavar at unm.edu
Fri Jul 16 00:40:00 UTC 1999
On Fri, 16 Jul 1999 Mark_Andrews at isc.org wrote:
> Date: Fri, 16 Jul 1999 10:18:10 +1000
> From: Mark_Andrews at isc.org
> To: Barry Margolin <barmar at bbnplanet.com>
> Cc: comp-protocols-dns-bind at moderators.uu.net
> Subject: Re: DNS query timeouts
>
>
> > In article <7mkht1$c4b$1 at oravannahka.Helsinki.FI>,
> > Tero A Kauppinen <takauppi at cc.helsinki.fi> wrote:
> > >We are currently using FreeBSD 3.2 & Bind 8.1.2 and are
> > >facing some problems when trying to resolve addresses. The setup we
> > >have is as follows:
> > >
> > > H -------- S ---------------- B -------- ( The Internet ) ---- X
> > > (host) (internal server) (bastion host) (target host)
> > >
> > >If H tries to query the address of host X, the operation fails for the
> > >first time. The problem, as I understand it, is with timing, i.e. S
> > >doesn't wait long enough for an answer from B. However, when the query
> > >is repeated, S has already got an answer for its previous query, and
> > >thus the answer can be found in the cache.
> > >
> > >How can I increase the time S waits for an answer from B before
> > >returning an error to H?
> >
> > I assume S is configured as a forwarding server, with:
> >
> > forwarders { <address of B>; }
> >
> > The trick is to put B's address in there multiple times, i.e.
> >
> > forwarders { <address of B>; <address of B>; }
> >
> > After S times out on the first address it will try again using the second
> > address.
> >
> > This worked in BIND 4; I hope they haven't added duplicate detection in
> > BIND 8, thinking that it would be an optimization.
> >
> > --
> > Barry Margolin, barmar at bbnplanet.com
> > GTE Internetworking, Powered by BBN, Burlington, MA
> > *** DON'T SEND TECHNICAL QUESTIONS DIRECTLY TO ME, post them to newsgroups.
> > Please DON'T copy followups to me -- I'll assume it wasn't posted to the grou
> > p.
> >
> >
> BIND 8.2.1 will try multiple times by default. The mechanism is
> the same as is used for normal nameservers rather than the linked
> list of old servers. BIND 8.2.1 has duplicate detection for
> forwarders.
>
> Mark
> --
> Mark Andrews, Internet Software Consortium
> 1 Seymour St., Dundas Valley, NSW 2117, Australia
> PHONE: +61 2 9871 4742 INTERNET: marka at isc.org
>
>
Greetings,
Can any of the bind experts answer (if possible or
applicable) the original question with respect to
what one can do to /etc/resolv.conf's entries?
Thanks,
Farid
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