In article <local.mail.freebsd-net/[EMAIL PROTECTED]> you write: >Lars Eggert wrote: >> >> > In article >> > <local.mail.freebsd-net/[EMAIL PROTECTED]> you write: >> > >Hello! >> > > >> > >It is important to me to have duration of TIME_WAIT state of TCP >> > >connection as short time as possible. >> > >> > Tweak net.inet.tcp.msl, which specifies the 2MSL timeout. >> >> And know what you are doing, it's there for a reason. If you need to >> dramatically change this value, I'd wager your system would benefit from a >> design change. >> >> Lars >> -- >> Lars Eggert <[EMAIL PROTECTED]> Information Sciences Institute >> http://www.isi.edu/larse/ University of Southern California > > >Alan Cox wrote: >| >| > Machine is web serwer with reather big traffic. Why there is >| > so much connections in TIME_WAIT state ? >| >| >| "2 mintues" may be how the Linux kernel does it, but it's not the way >| TCP says it should be done. >| >| TIME_WAIT should last for 2*MSL (maximum segment lifetime). I know >it's >| hard to calculate MSL, and if you make up a hard-coded value it has to >| be long enough for the slowest connections. It could be that FreeBSD >| 4.0 does do this calculation. If we can calculate semi-accurate MSLs >| for each connection, TIME_WAIT states would be minimized. >| >| Even over a slow Internet link, the MSL can't be much longer than 10 >| seconds or so. By then a segment has either been TTL'd out, or is >| lost. I don't buy "MSL == 1 minute" at all. > >How to turn on this calculation for 4.x ?
Unfortunately, this is not calculated; we still rely on a static (default 30sec) MSL quiet period. Ideally, it should be possible to set MSL based on some multiple of RTT for the connection, and default to a hard coded value if there are not enough samples to calculate RTT. -- Jonathan To Unsubscribe: send mail to [EMAIL PROTECTED] with "unsubscribe freebsd-net" in the body of the message
