From owner-freebsd-hackers Fri May 22 13:27:46 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id NAA09534 for freebsd-hackers-outgoing; Fri, 22 May 1998 13:27:46 -0700 (PDT) (envelope-from owner-freebsd-hackers@FreeBSD.ORG) Received: from att.com (kcgw2.att.com [192.128.133.152]) by hub.freebsd.org (8.8.8/8.8.8) with SMTP id NAA09513 for ; Fri, 22 May 1998 13:27:31 -0700 (PDT) (envelope-from sbabkin@dcn.att.com) From: sbabkin@dcn.att.com Received: by kcgw2.att.com; Fri May 22 15:08 CDT 1998 Received: from dcn71.dcn.att.com ([135.44.192.112]) by kcig2.att.att.com (AT&T/GW-1.0) with ESMTP id PAA21748 for ; Fri, 22 May 1998 15:27:15 -0500 (CDT) Received: by dcn71.dcn.att.com with Internet Mail Service (5.0.1458.49) id ; Fri, 22 May 1998 16:27:15 -0400 Message-ID: To: mark@vmunix.com Cc: hackers@FreeBSD.ORG Subject: RE: TIME_WAIT/FIN_WAIT_2... Date: Fri, 22 May 1998 16:27:13 -0400 X-Priority: 3 MIME-Version: 1.0 X-Mailer: Internet Mail Service (5.0.1458.49) Content-Type: text/plain Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG > ---------- > From: Mark Mayo[SMTP:mark@vmunix.com] > Sent: Friday, May 22, 1998 1:54 PM > To: Jim Shankland; tlambert@primenet.com > Cc: hackers@FreeBSD.ORG; isp@FreeBSD.ORG > Subject: Re: TIME_WAIT/FIN_WAIT_2... > > On Fri, May 22, 1998 at 09:43:04AM -0700, Jim Shankland wrote: > > > So what you're really seeing, Mark, is connections in FIN_WAIT_2 > state, > > where the web server has closed the socket, but the client has never > > indicated that it is done sending. These hang around for about 11 > > minutes, then disappear. (Of course, more take their place.) > > > > The reason for the 11 minute wait is so that if the client is just > > slow going through its shutdown stuff, the server can still walk the > > client through an orderly close. On the other hand, maybe 11 > minutes > > is too long? I'll bet nothing terrible happens if that timeout > drops > > to 1 minute ... or 30 seconds. Even 0 would at worst lead to some > > unnecessary RST's on closing connections. Anyone have any thoughts > on > > this? > > I'm thinking that setting it to 2MSL, like TIME_WAIT might be okay, > and still relatively conservative. 4 minutes is not bad, and on a > It occurred that I'm reading the McKusick & other's book right now and this is the exact quote on the TCP implementation: "In addition, 4.4BSD starts the 2MSL timer when FIN_WAIT_2 state is entered after the user has closed." So, probably this is the reason why you don't see so many hanging sockets in FIN_WAIT_2 on FreeBSD. -Serge To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message