From owner-freebsd-net@FreeBSD.ORG Sat May 28 13:10:01 2011 Return-Path: Delivered-To: freebsd-net@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 44A31106564A for ; Sat, 28 May 2011 13:10:01 +0000 (UTC) (envelope-from kmacybsd@gmail.com) Received: from mail-vw0-f54.google.com (mail-vw0-f54.google.com [209.85.212.54]) by mx1.freebsd.org (Postfix) with ESMTP id E9A308FC14 for ; Sat, 28 May 2011 13:10:00 +0000 (UTC) Received: by vws18 with SMTP id 18so2642477vws.13 for ; Sat, 28 May 2011 06:10:00 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:sender:in-reply-to:references:date :x-google-sender-auth:message-id:subject:from:to:cc:content-type; bh=P5ABuQJe0/XrDz4kOAHWJaTnQxV2JR6tszfEwQZX7HQ=; b=Cw2rUtFLa3E7horxpIOCqXGjGAiFc6TCaBm31YihdvPlApRq1a/DD9EtgxLOvchluu EPGkaTG/XlVuarY6dfMREED053W4L8KJft0D3RDbrcA349VmdO1gGygt2T36kjhukBMc oP/Cp3h3mio21fJl3MTv0JS16o5pIXtSyJYwM= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:sender:in-reply-to:references:date :x-google-sender-auth:message-id:subject:from:to:cc:content-type; b=nQn4eWLIvDBmRWVbx9KPmAu3YWd1BssGC6RH8PBch0nWg13f/kA7K/HcpUqDHJz7q1 UcKMZJoLmZc7UykUdlzt1esukGxsv49DdRAW3cJbWU+Cv1Fj/eyDK2G3Lh92zI72WKK5 X/9pqKY+oj1PikrIgIjRyzJcstIMTCkWiVsBw= MIME-Version: 1.0 Received: by 10.52.99.106 with SMTP id ep10mr4430529vdb.46.1306588200027; Sat, 28 May 2011 06:10:00 -0700 (PDT) Sender: kmacybsd@gmail.com Received: by 10.52.186.67 with HTTP; Sat, 28 May 2011 06:09:59 -0700 (PDT) In-Reply-To: References: Date: Sat, 28 May 2011 15:09:59 +0200 X-Google-Sender-Auth: NGRLnxT78J33EZ4qGZ2357Vy5Rw Message-ID: From: "K. Macy" To: Tom Worster Content-Type: text/plain; charset=ISO-8859-1 Cc: freebsd-net@freebsd.org Subject: Re: Can net.inet.tcp.msl be set per interface? X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 28 May 2011 13:10:01 -0000 Unfortunately msl is a global variable: tcp_timer.c: int tcp_msl; SYSCTL_PROC(_net_inet_tcp, OID_AUTO, msl, CTLTYPE_INT|CTLFLAG_RW, &tcp_msl, 0, sysctl_msec_to_ticks, "I", "Maximum segment lifetime"); Sockets or rather inpcbs in timewait are maintained on a per-vnet list. Since tcp_twstart is called from tcp_do_segment in tcp_input.c it does actually have access to the mbuf triggering the state transition and thus the receiving interface. As far as I can tell, changing the behavior to what you're asking for would not be difficult. Cheers, Kip On Fri, May 27, 2011 at 4:59 PM, Tom Worster wrote: > [[I asked this yesterday on -questions, probably the wrong list]] > > If a server has one interface to the Internet and another interface to a > switch connecting to a few other servers, it seems TCP's MSL value might > reasonably be set a lot lower on the private interface. > > I'm specifically thinking of a lot of short MySQL connections(*) between > the > servers on the private LAN. The average number of MySQL client connections > in TIME_WAIT will be proportional to MSL. And, while the circumstances > under which a long MSL would help anything are unimaginable on the LAN, > they are not on the Internet. > > So can net.inet.tcp.msl be set per interface? > > (*) Or similar: Sphinx, memcached, perhaps. > > Tom > > > > _______________________________________________ > freebsd-net@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-net > To unsubscribe, send any mail to "freebsd-net-unsubscribe@freebsd.org" >