From owner-freebsd-net Mon Jul 1 21:48:54 2002 Delivered-To: freebsd-net@freebsd.org Received: from mx1.FreeBSD.org (mx1.FreeBSD.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 3E0B037B400 for ; Mon, 1 Jul 2002 21:48:50 -0700 (PDT) Received: from out1.mx.nwbl.wi.voyager.net (out1.mx.nwbl.wi.voyager.net [169.207.3.119]) by mx1.FreeBSD.org (Postfix) with ESMTP id 9607543E0A for ; Mon, 1 Jul 2002 21:48:49 -0700 (PDT) (envelope-from silby@silby.com) Received: from pop0.nwbl.wi.voyager.net (pop0.nwbl.wi.voyager.net [169.207.1.115]) by out1.mx.nwbl.wi.voyager.net (8.12.3/8.11.4/1.7) with ESMTP id g624mmiB019101; Mon, 1 Jul 2002 23:48:48 -0500 Received: from [10.1.1.6] (d185.as13.nwbl0.wi.voyager.net [169.207.136.251]) by pop0.nwbl.wi.voyager.net (8.10.2/8.10.2) with ESMTP id g624mlX48475; Mon, 1 Jul 2002 23:48:47 -0500 (CDT) Date: Mon, 1 Jul 2002 23:51:42 -0500 (CDT) From: Mike Silbersack To: pavel@alum.mit.edu Cc: net@FreeBSD.ORG Subject: Re: questions about TCP RST validity In-Reply-To: <200207020353.g623rUR62985@scout.networkphysics.com> Message-ID: <20020701234858.G87544-100000@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 Mon, 1 Jul 2002, Tom Pavel wrote: > Here is a trace to illustrate: > > 09:05:35.956066 AA.80 > BB.61390: . 3568529946:3568531406(1460) ack 2597111261 win 4380 (DF) > 09:05:36.961787 AA.80 > BB.61390: . 3568529946:3568531406(1460) ack 2597111261 win 4380 (DF) > 09:05:38.973207 AA.80 > BB.61390: . 3568529946:3568531406(1460) ack 2597111261 win 4380 (DF) Is this a real trace? It looks highly irregular to me. I don't see why BB isn't RSTing each packet, and AA looks to be retransmitting way too quickly. > In any event, though, it seems to me relatively harmless to have AA > accept seqnums "slightly" to the left of its current advertised window > (say last_ack_sent - rcv_wnd). This would save a bunch of needless > retransmits and it would clean up the control block much sooner than > letting AA timeout on retransmitting. > > What collective wisdom do folks have about this? > > > Tom Pavel I'm not sure doubling the "RST window" is a good idea. With window sizes increasing as they are, that could become a significant issue as time goes on. How about one MSS worth of window or something similar? Mike "Silby" Silbersack To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-net" in the body of the message