Date: Tue, 28 Aug 2007 12:35:20 +0200 From: Frank Altpeter <frank@altpeter.de> To: freebsd-questions@freebsd.org Subject: lost DNS queries Message-ID: <20070828103520.GB37646@corpex.de>
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Hi list,
I'm trying to resolve a strange problem on my DNS resolver system for some
time now, and still have no clue where to catch the reason. Perhaps
someone here has some hints for me...
The prerequisites:
DNS Server with FreeBSD 6.2-RELEASE-p4 running bind as resolver (hardware
sufficient, e.g. dual Xeon 3.0 GHz with 2GB RAM, OS on SCSI RAID1).
DNS client machine connected via HP ProCurve switch and in the same VLAN
as the DNS server machine.
Test software: dnsperf
Command executed: dnsperf -d /tmp/input-10000.txt -s ${DNSSERVER} -c -A
Result output of the command:
----------------------------------------------------------------------------
Parse input file: once
Ended due to: reaching end of file
Queries sent: 10000 queries
Queries completed: 9770 queries
Queries lost: 230 queries
Returned NOERROR: 7235 queries
Returned SERVFAIL: 107 queries
Returned NXDOMAIN: 2428 queries
Avg request size: 41 bytes
Avg response size: 184 bytes
Percentage completed: 97.70%
Percentage lost: 2.30%
Started at: Tue Aug 28 12:22:51 2007
Finished at: Tue Aug 28 12:25:30 2007
Ran for: 159.355209 seconds
Queries per second: 61.309574 qps
----------------------------------------------------------------------------
I tweaked several settings on the dns server to reduce the percentage
lost:
sysctl net.inet.icmp.icmplim=1024
sysctl net.inet.raw.recvspace=65536
sysctl net.inet.udp.recvspace=256000
sysctl net.inet.tcp.sendspace=65536
sysctl net.inet.tcp.recvspace=65536
sysctl kern.ipc.somaxconn=512
sysctl kern.ipc.maxsockbuf=8388608
but still i'm not able to find a reason why so much queries are lost and i
don't see any reason for this. It even happens when dnsperf is started
directly on the dns server.
Does anyone has an idea where to search for this problem?
Le deagh dhùraghd,
Frank Altpeter
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