From owner-freebsd-net Tue Aug 18 14:57:59 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id OAA06356 for freebsd-net-outgoing; Tue, 18 Aug 1998 14:57:59 -0700 (PDT) (envelope-from owner-freebsd-net@FreeBSD.ORG) Received: from resnet.uoregon.edu (resnet.uoregon.edu [128.223.144.32]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id OAA06334; Tue, 18 Aug 1998 14:57:50 -0700 (PDT) (envelope-from dwhite@resnet.uoregon.edu) Received: from localhost (dwhite@localhost) by resnet.uoregon.edu (8.8.5/8.8.8) with SMTP id OAA03613; Tue, 18 Aug 1998 14:57:10 -0700 (PDT) (envelope-from dwhite@resnet.uoregon.edu) Date: Tue, 18 Aug 1998 14:57:10 -0700 (PDT) From: Doug White To: Kevin Kyeong-il CHOI cc: FreeBSD Question , FreeBSD Net Subject: Re: Questions on TCPDUMP, TCP Window Size In-Reply-To: <000501bdca86$55eac6c0$52099584@pc-kichoi.cst.cnes.fr> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-net@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org On Tue, 18 Aug 1998, Kevin Kyeong-il CHOI wrote: > Hi, > > I have another question. > I'm actually working on the TCP observation. > I saw the article http://www.psc.edu/networking/perf_tune.html > Then, I tried to change the system variables of FreeBSD 2.2.6 > to obtain a large TCP window size. > > (1) First question. > I want to make the RFC1323 works on FreeBSD 2.2.6. > Is there any special procedure I need to do ? As long as 'tcp_extensions=YES' in rc.conf, then those extensions are enabled, yes. You can confirm with the command: sysctl net.inet.tcp.rfc1323 If it's set to 1 then it is enabled. > (2) Second. > Once the (1) question resolved, > How can I make TCP's option "Window Scale" work on > any connection such as FTP ? These optimizations are handled automatically, AFAIK. > (3) Third > TCPDUMP, as a real good utility to observe the traffic > on TCP connection, I really want to use this. BUT, But, > whenever I launch this "tcpdump [enter]", it tells me, > > tcpdump: /dev/bpf0: Device not configured. > > I tried to change chmod 666 /dev/bpf0, but no succeed. > > What is the problem here ? You need to build a new kernel with pseduo-device bpfilter 4 in the config file. Doug White | University of Oregon Internet: dwhite@resnet.uoregon.edu | Residence Networking Assistant http://gladstone.uoregon.edu/~dwhite | Computer Science Major To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-net" in the body of the message