BIND 9.2.1 and TCP

Mark_Andrews at isc.org Mark_Andrews at isc.org
Thu Nov 7 06:19:05 UTC 2002


> 
> The request is for a single A record, ( nash 3600 IN A 192.168.0.1 ), would t
> his be too large to fit in a UDP packet.  Also we have BIND 8 servers that se
> rve the same information and they do not revert to TCP for these records.  Co
> uld this possibly be a misconfiguration on my part, or is there no way to res
> trict the server to only using udp?
> Thanks,
> Zack

	Why don't you show us what 'dig +ignoretc +search <name>' returns
	then 'dig +search <name>'.

	Mark
> 
> -----Original Message-----
> From: Mark.Andrews at isc.org [mailto:Mark.Andrews at isc.org]
> Sent: Wednesday, November 06, 2002 4:25 PM
> To: Nash, Zack
> Cc: bind-users at isc.org
> Subject: Re: BIND 9.2.1 and TCP
> 
> 
> 
> > Hello,
> > 	I have noticed that my BIND 9.2.1 servers are requesting that my DNS Cl
> > ients use TCP rather than UDP to resolve hostnames, for all queries against
>  t
> > his server.
> > 	My understanding is that UDP is used unless the packet is too large the
> > n the server will request a TCP connection from the client.  I have seen th
> is
> >  occur for queries of a single A record.  Is this behavior a bug or is this
>  a
> >  new standard that is being implemented with the advent of BIND 9?
> > Thanks,
> > Zack
> 
> 	Well the answers must be too big to fit in the space available in a
> 	UDP response.  Remember the authority section can also trigger TC.
> 
> 	Mark
> --
> Mark Andrews, Internet Software Consortium
> 1 Seymour St., Dundas Valley, NSW 2117, Australia
> PHONE: +61 2 9871 4742                 INTERNET: Mark.Andrews at isc.org
> 
> 
--
Mark Andrews, Internet Software Consortium
1 Seymour St., Dundas Valley, NSW 2117, Australia
PHONE: +61 2 9871 4742                 INTERNET: Mark.Andrews at isc.org


More information about the bind-users mailing list