From owner-freebsd-net Thu Sep 26 3: 8:33 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 C0EF737B401 for ; Thu, 26 Sep 2002 03:08:32 -0700 (PDT) Received: from relay1.macomnet.ru (relay1.macomnet.ru [195.128.64.10]) by mx1.FreeBSD.org (Postfix) with ESMTP id 75A0843E42 for ; Thu, 26 Sep 2002 03:08:31 -0700 (PDT) (envelope-from maxim@macomnet.ru) Received: from news1.macomnet.ru (news1.macomnet.ru [195.128.64.14]) by relay1.macomnet.ru (8.11.6/8.11.6) with ESMTP id g8QA6vw602436; Thu, 26 Sep 2002 14:06:57 +0400 (MSD) Date: Thu, 26 Sep 2002 14:06:56 +0400 (MSD) From: Maxim Konovalov To: Mike Silbersack Cc: Giorgos Keramidas , Subject: Re: mbuf chain In-Reply-To: <20020926025730.J6503-100000@patrocles.silby.com> Message-ID: <20020926140529.P64981-100000@news1.macomnet.ru> References: <20020926025730.J6503-100000@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 [...] > I don't believe that mbuf fragments have any relationship to IP > fragmentation. > > And while you mention it, the IP fragmentation handling code is another > place where we need to add mbuf merging/chaining. > > I've been thinking about this, actually. How many IP fragments will a > packet ever truly have? If you assume a 1500 byte ethernet packet broken > into 200 byte chunks, that's < 8. If you break a jumbo frame into 1500 > byte packets, that's < 7. Can there be any normal use of fragmentation > that would produce more than 10 or so fragments? Also, will overlapping > fragments really ever be seen, or can we just assume that's a sign of > abuse? > > Sorry for the sudden change of direction for this thread, I've been > pondering how to improve our resistance to mbuf exhaustion through ip > frags. There is net.inet.ip.maxfragpackets but IMHO net.inet.ip.maxfragperpacket will be useful too. -- Maxim Konovalov, MAcomnet, Internet Dept., system engineer phone: +7 (095) 796-9079, mailto:maxim@macomnet.ru To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-net" in the body of the message