From owner-freebsd-net Wed Apr 17 12:34:25 2002 Delivered-To: freebsd-net@freebsd.org Received: from patrocles.silby.com (d152.as2.nwbl0.wi.voyager.net [169.207.95.26]) by hub.freebsd.org (Postfix) with ESMTP id 87E9837B6B1 for ; Wed, 17 Apr 2002 12:28:50 -0700 (PDT) Received: from patrocles.silby.com (localhost [127.0.0.1]) by patrocles.silby.com (8.12.2/8.12.2) with ESMTP id g3I1S2Lx016597; Wed, 17 Apr 2002 20:28:02 -0500 (CDT) (envelope-from silby@silby.com) Received: from localhost (silby@localhost) by patrocles.silby.com (8.12.2/8.12.2/Submit) with ESMTP id g3I1Rv2i016594; Wed, 17 Apr 2002 20:28:01 -0500 (CDT) X-Authentication-Warning: patrocles.silby.com: silby owned process doing -bs Date: Wed, 17 Apr 2002 20:27:57 -0500 (CDT) From: Mike Silbersack To: Bill Fenner Cc: freebsd-net@FreeBSD.ORG Subject: Re: What does FreeBSD do when listen queue is full ? In-Reply-To: <200204171909.MAA01611@windsor.research.att.com> Message-ID: <20020417201853.C16380-100000@patrocles.silby.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-net@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.org On Wed, 17 Apr 2002, Bill Fenner wrote: > Boy, I hope not. Incoming SYNs should be ignored if the backlog > is met, so that the client can retransmit them. I know Microsoft > decided to use RST as a "my queue is full" indicator, but I hope > we're not following in their footsteps!... > > Bill Actually, I read the code slightly wrong. We don't send a RST, we just silently drop the connection. However, at the point we're talking about, we're already past the 3-way handshake, so either way the connection has been lost. Heh, actually, I take that back. With a syncookie, a retransmitted ACK should end up reestablishing the connection. Clever... I think that you're referring to the case where we receive an initial SYN, and the listen queue is full. With the syncache/syncookies, this is no longer a problem; either a syn cookie is returned, or the syn is silently dropped (depending on whether or not syn cookies are enabled.) With the pre-syncache code, yes, a RST was sent at that time. Mike "Silby" Silbersack To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-net" in the body of the message