Date: Sat, 20 Aug 2005 19:50:18 +0200 From: Christian Vogt <chvogt@tm.uka.de> To: Andre Oppermann <andre@freebsd.org> Cc: freebsd-net@freebsd.org, TM-RO2 <tm-ro2@tm.uka.de> Subject: Re: Deactivate TCP Hostcache? Message-ID: <43076D5A.5070703@tm.uka.de> In-Reply-To: <43076895.7C238E6E@freebsd.org> References: <4307628A.9050102@tm.uka.de> <43076895.7C238E6E@freebsd.org>
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This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enig04BF8EF4F8D0F70D4DBDF92D Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Hi Andre, thanks for the info. What I did is this: I changed the TCP_HOSTCACHE_PRUNE constant from 5 minutes to 5 seconds. After one experimentation run, my scripts call 'sysctl net.inet.tcp.hostcache.purge=1 && sleep 5'. This guarantees that there is no remaining info in the TCP hostcache when the next experimentation run takes off. Bye, - Christian -- Christian Vogt, Institute of Telematics, University of Karlsruhe www.tm.uka.de/~chvogt/pubkey/ Andre Oppermann wrote: > Christian Vogt wrote: > >>Hi everybody, >> >>is there a way to deactivate the TCP hostcache? >> >>I could modify the kernel, but probably there is a more convenient way >>to do this. > > > No, there is no other way. > > >>The reason I want to deactivate the hostcache is because I am doing >>experiments and later measurements should not be different than earlier >>ones due to cached information. > > > Comment out the tcp_hc_update() call on line 737 in netinet/tcp_subr.c > and it won't cache metrics anymore. The discovered path MTU is still > stored though. > --------------enig04BF8EF4F8D0F70D4DBDF92D Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.0 (GNU/Linux) iD8DBQFDB21fwstEk8gl2rURAirqAKDVGf56jKQqdlVLJSOLYDVpVbiKhwCeN5m5 5OkeOJXLiuatvEQHUd7NHhw= =CPP4 -----END PGP SIGNATURE----- --------------enig04BF8EF4F8D0F70D4DBDF92D--
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