From owner-freebsd-questions Fri Feb 21 17:41:32 2003 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 0C75A37B401 for ; Fri, 21 Feb 2003 17:41:31 -0800 (PST) Received: from mailsrv.otenet.gr (mailsrv.otenet.gr [195.170.0.5]) by mx1.FreeBSD.org (Postfix) with ESMTP id D433643FCB for ; Fri, 21 Feb 2003 17:41:29 -0800 (PST) (envelope-from keramida@ceid.upatras.gr) Received: from gothmog.gr (patr364-a26.otenet.gr [195.167.109.58]) by mailsrv.otenet.gr (8.12.6/8.12.6) with ESMTP id h1M1fA2O000251; Sat, 22 Feb 2003 03:41:20 +0200 (EET) Received: from gothmog.gr (gothmog [127.0.0.1]) by gothmog.gr (8.12.7/8.12.7) with ESMTP id h1M1XSO6018776; Sat, 22 Feb 2003 03:39:58 +0200 (EET) (envelope-from keramida@ceid.upatras.gr) Received: (from giorgos@localhost) by gothmog.gr (8.12.7/8.12.7/Submit) id h1LKWHos073890; Fri, 21 Feb 2003 22:32:17 +0200 (EET) (envelope-from keramida@ceid.upatras.gr) Date: Fri, 21 Feb 2003 22:32:17 +0200 From: Giorgos Keramidas To: johnsonest@hotmail.com Cc: freebsd-questions@freebsd.org, gary.thomas@mind.be Subject: Re: some question Message-ID: <20030221203217.GA70911@gothmog.gr> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: owner-freebsd-questions@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG On 2003-02-20 16:46, ?? ?? wrote: > hi,i have a question about tcp/ip stack,could you help me? > when we send a tcp packet with tcp_maxopt(tcp_maxopt = min(my > mss,mss offerd by opposite socket) +length of TCP options,as ecos > does in function tcp_mss() of the file tcp_input.c) to IP,and IP > insert some IP options into packet,so maybe length of whole IP > packet > ifp->mtu,so Ip must fragment this tcp packet,and TCP failed > to avoid fragmenting in host itsself. > as we know,TCP always avoid to fragment as possible,maybe the > condition above does not occur often,but it is possible. > right? > or wrong,please tell me,Thank you very much! The comment above tcp_mss() says: * NOTE that this routine is only called when we process an incoming * segment, for outgoing segments only tcp_mssopt is called. So, it won't be called for frames created by ip_output() :-) To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message