From: Vesna Vranesic (vesna.vranesic@RZB.AT)
Date: Fri Dec 27 2002 - 10:43:43 EST
Hey guys, its Christmas time. No reason to say: grrrrrrrrr. Cause.... There
is a possibility....
On AIX, a DNS query will wait a total of (like you said) 75 seconds before
failing over to the second nameserver entry in the resolv.conf.
The 75 sec timeout period comes from two values RES_TIMEOUT and RES_RETRY.
" The way it works is the dns client will try to contact the dns server,
then if it doesn't get an answer back it will wait 5 seconds and try
again, then it will wait 10 secs and try again, 20 sec and try again, 40
secs and try again. "
Hence for default values of RES_TIMEOUT=5 sec
and RES_RETRY=4 sec and for each retry
the inital RES_TIMEOUT is multiplied by
2
=> 5 + 10 + 20 + 40 = 75 seconds
So, change also the RES_RETRY value. Afterwards it should work.
Ciao
Vesna
John.Jolet@MISYSHEALTHCARE.COM@Princeton.EDU am 27.12.2002 15:29:22
Bitte antworten an aix-l@princeton.edu@inet
Gesendet von: aix-l@Princeton.EDU
An: aix-l@Princeton.EDU
Kopie:
Thema: Re: AIX 4.3.3 DNS Timeouts?
i've been looking for an answer to this one for a year. as far as I know,
that timeout value is not configurable.....grrrr.
-----Original Message-----
From: Cooper, Keith [mailto:kcooper@SELFREGIONAL.ORG]
Sent: Thursday, December 26, 2002 4:24 PM
To: aix-l@Princeton.EDU
Subject: AIX 4.3.3 DNS Timeouts?
Hi Guru's. Hope all had a Merry Christmas!
Question:
I am running AIX 4.3.3. I have two nameservers
set up in /etc/resolv.conf.
If I do a nslookup on a machine when both nameservers are up; no problem.
If I do the same nslookup when the first (in the list) nameserver is down,
I have to
wait approximately 75-90 seconds for the second nameserver to get the
request
and reply.
What can be done to get the timeout for the first request quicker? I have
serched the
Archives and the internet and the only thing that I have found is to set an
environment
Variable RES_TIMEOUT to a small number, but that does not work.
Any help would be much appreciated.
Thanks in advance.
Keith C.
Keith Cooper
Unix Administrator
Self Regional Healthcare
Greenwood, SC USA
IBM AIX System Admin 4.3/System User, A+, Linux+,
Network+, I-Net+ Certified, Compaq APS Certified ? Notebooks &
Desktop/Workstations.
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