From owner-freebsd-net Sun Mar 5 7:15:49 2000 Delivered-To: freebsd-net@freebsd.org Received: from quercus.ifn.fr (mailhost.ifn.fr [62.161.215.67]) by hub.freebsd.org (Postfix) with ESMTP id 4329F37BA20 for ; Sun, 5 Mar 2000 07:15:45 -0800 (PST) (envelope-from rguyom@mail.dotcom.fr) Received: from pingoo.ifn.fr ([192.9.200.33]) by quercus.ifn.fr with SMTP (Microsoft Exchange Internet Mail Service Version 5.5.2232.9) id FLZQQKGV; Sun, 5 Mar 2000 16:15:42 +0100 Received: (from rguyom@localhost) by pingoo.ifn.fr (8.9.3/8.9.3) id QAA22334; Sun, 5 Mar 2000 16:15:41 +0100 Date: Sun, 5 Mar 2000 16:15:40 +0100 From: =?iso-8859-1?Q?R=E9mi_Guyomarch?= To: Michael Hartung Cc: freebsd-net@FreeBSD.ORG Subject: Re: Answer keep-alive requests Message-ID: <20000305161540.A22005@pingoo.ifn.fr> References: <38C23F61.853FEE66@zkom.de> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8bit X-Mailer: Mutt 1.0.1i In-Reply-To: <38C23F61.853FEE66@zkom.de>; from hartung@zkom.de on Sun, Mar 05, 2000 at 12:05:05PM +0100 Sender: owner-freebsd-net@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org On Sun, Mar 05, 2000 at 12:05:05PM +0100, Michael Hartung wrote: > Hi Folks, > > a customers hardware (fucking S7 CP from Siemens) loves to emit > keep-alive packets once a TCP-connection is established. No chance to > turn this off (Siemens doesn’t care about RFC1122). How can I force our > FreeBSD 3.4 system to answer these packets. Probably a switch in > /sys/netinet/tcp_timer.c...? Compile the kernel and everything is > fine...? If I read /usr/src/sys/netinet/tcp* correctly, you shouldn't have to do anything to answer keepalive messages. In fact keepalive messages are just 0 bytes packets which repeat the last ack sent to the peer. There is a few sysctl variables which allow you to customize the rate your system *sends* those keepalive messages, but none to answer them, because the answer is part of the normal TCP processing. Am I right ? :-) To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-net" in the body of the message