From owner-freebsd-hackers Tue Jul 10 15: 0:53 2001 Delivered-To: freebsd-hackers@freebsd.org Received: from elvis.mu.org (elvis.mu.org [216.33.66.196]) by hub.freebsd.org (Postfix) with ESMTP id 0593837B403 for ; Tue, 10 Jul 2001 15:00:51 -0700 (PDT) (envelope-from billf@elvis.mu.org) Received: by elvis.mu.org (Postfix, from userid 1098) id 0CCC581D06; Tue, 10 Jul 2001 17:00:51 -0500 (CDT) Date: Tue, 10 Jul 2001 17:00:50 -0500 From: Bill Fumerola To: Joseph Lekostaj Cc: hackers@freebsd.org Subject: Re: TCP Window Size Message-ID: <20010710170050.F47870@elvis.mu.org> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5i In-Reply-To: ; from lekostaj@mcs.anl.gov on Tue, Jul 10, 2001 at 02:54:41PM -0500 X-Operating-System: FreeBSD 4.3-FEARSOME-20010617 i386 Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG On Tue, Jul 10, 2001 at 02:54:41PM -0500, Joseph Lekostaj wrote: > > I've been trying to up my TCP window size from the default 16K and it's caused nothing but problems. From the info I've found so far, these are the sysctl i've changed: > > kern.ipc.maxsockbuffer=2097152 > net.inet.tcp.rfc1323=1 > net.inet.tcp.sendspace=524288 > net.inet.tcp.recvspace=524288 Good christ thats a lot of memory per socket. kern.ipc.maxsockets is also fairly important to know here too. Nothing is going to prevent the above values from getting out of hand, short of a huge amount of memory dedicated to sockets.. see below... > But if I do that, on boot I get all sorts of error messages about buffer space. i.e.: > > Jul 9 11:53:20 ccn64 portmap[180]: cannot create tcp socket: No buffer space available > Jul 9 11:53:21 ccn64 inetd[199]: shell/tcp: socket: No buffer space available > Jul 9 11:53:21 ccn64 inetd[199]: login/tcp: socket: No buffer space available > Jul 9 11:58:55 ccn64 RPC::PlClient[243]: Cannot connect: No buffer space available > Jul 9 11:58:55 ccn64 RPC::PlClient[246]: Cannot connect: No buffer space available > > Is there anything I'm missing? The memory to support blowing 524k of memory per socket? As I recall this memory is eaten as the sockets are created. If you really think you need that much memory (you don't), you're going to need to increase your socket memory to a lot more then 2097152.... I'd personally suggest just tuning net.inet.tcp.*space to 64k at most. -- Bill Fumerola - security yahoo / Yahoo! inc. - fumerola@yahoo-inc.com / billf@FreeBSD.org To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message