From owner-freebsd-questions@FreeBSD.ORG Mon Mar 21 18:52:30 2005 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id F1BB316A4CE for ; Mon, 21 Mar 2005 18:52:30 +0000 (GMT) Received: from uni-sb.de (uni-sb.de [134.96.252.33]) by mx1.FreeBSD.org (Postfix) with ESMTP id F08CC43D49 for ; Mon, 21 Mar 2005 18:52:29 +0000 (GMT) (envelope-from robertgogolok@web.de) Received: from cs.uni-sb.de (cs.uni-sb.de [134.96.252.31]) by uni-sb.de (8.13.3/2005020900) with ESMTP id j2LIqSkj000050; Mon, 21 Mar 2005 19:52:28 +0100 (CET) Received: from mail.cs.uni-sb.de (mail.cs.uni-sb.de [134.96.254.200]) by cs.uni-sb.de (8.13.3/2005011400) with ESMTP id j2LIqRcY013807; Mon, 21 Mar 2005 19:52:27 +0100 (CET) Received: from xantippe (xantippe.cs.uni-sb.de [134.96.240.13]) by mail.cs.uni-sb.de (8.13.3/2005020900) with ESMTP id j2LIqRhv018228; Mon, 21 Mar 2005 19:52:27 +0100 (CET) X-Authentication-Warning: mail.cs.uni-sb.de: Host xantippe.cs.uni-sb.de [134.96.240.13] claimed to be xantippe Received: from eugene.cs.uni-sb.de ([127.0.0.1]) [134.96.240.6] by xantippe with esmtp (Exim 3.35 #1 (Debian))id 1DDS0n-0007h3-00; Mon, 21 Mar 2005 19:52:26 +0100 Message-ID: <423F17D9.70802@web.de> Date: Mon, 21 Mar 2005 19:52:09 +0100 From: Robert Gogolok User-Agent: Mozilla Thunderbird 1.0 (X11/20050313) X-Accept-Language: en-us, en MIME-Version: 1.0 To: Charles Swiger References: <423EFE41.6040805@web.de> <56b90b3668acea792519e1e70a7b837a@mac.com> <423F05F2.3010101@web.de> <7c82a2d1780970b84810aefc59bdb295@mac.com> In-Reply-To: <7c82a2d1780970b84810aefc59bdb295@mac.com> X-Enigmail-Version: 0.89.6.0 X-Enigmail-Supports: pgp-inline, pgp-mime Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit cc: freebsd-questions@freebsd.org Subject: Re: FIN_WAIT_2 X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 21 Mar 2005 18:52:31 -0000 Charles Swiger wrote: > FIN_WAIT_2 is a name describing the state of a TCP connection. It's > defined in a state diagram in RFC-793. But otherwise, your description > is pretty good: > [ ... ] > | CLOSE +---------+ > | ------- | ESTAB | > | snd FIN +---------+ > | CLOSE | | rcv FIN > V ------- | | ------- > +---------+ snd FIN / \ snd ACK +---------+ > | FIN |<----------------- ------------------>| CLOSE | > | WAIT-1 |------------------ | WAIT | > +---------+ rcv FIN \ +---------+ > | rcv ACK of FIN ------- | CLOSE | > | -------------- snd ACK | ------- | > V x V snd FIN V > +---------+ +---------+ +---------+ > |FINWAIT-2| | CLOSING | | LAST-ACK| > +---------+ +---------+ +---------+ > | rcv ACK of FIN | rcv ACK of FIN | > | rcv FIN -------------- | Timeout=2MSL -------------- | > | ------- x V ------------ x V > \ snd ACK +---------+delete TCB +---------+ > ------------------------>|TIME WAIT|------------------>| CLOSED | > +---------+ +---------+ > > TCP Connection State Diagram > Figure 6. I've looked at the "Closing a Connection" chapter from the RFC and tried to understand it. The state diagram above shows that from the FINWAIT-2 state there is only one possible way to reach TIME WAIT. So FreeBSD must be using another extension of the RFC-793, when it's sending ACK messages in the FINWAIT-2 state? Wow, I'm confused at this point, I have a linux box here which was the previous webserver, and I can't remember seeing ACK's hitting the firewall logs as it is now with the FreeBSD webserver. Greetings, Robert!