From owner-freebsd-net@FreeBSD.ORG Thu Feb 9 12:27:15 2006 Return-Path: X-Original-To: net@freebsd.org 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 C892716A420; Thu, 9 Feb 2006 12:27:15 +0000 (GMT) (envelope-from ricardo_bsd@yahoo.com.br) Received: from maritaca.epm.br (disrouter.epm.br [200.17.25.161]) by mx1.FreeBSD.org (Postfix) with ESMTP id 237F143D81; Thu, 9 Feb 2006 12:27:09 +0000 (GMT) (envelope-from ricardo_bsd@yahoo.com.br) Received: from localhost (localhost.localdomain [127.0.0.1]) by maritaca.epm.br (Postfix) with ESMTP id B72863B4D; Thu, 9 Feb 2006 10:27:07 -0200 (BRDT) Received: from [172.22.1.166] (ricardo.epm.br [172.22.1.166]) by maritaca.epm.br (Postfix) with ESMTP id 589253B40; Thu, 9 Feb 2006 10:27:03 -0200 (BRDT) Message-ID: <43EB3502.8060701@yahoo.com.br> Date: Thu, 09 Feb 2006 10:26:42 -0200 From: "Ricardo A. Reis" User-Agent: Thunderbird 1.5 (X11/20060126) MIME-Version: 1.0 To: Robert Watson References: <43EA25EF.3020105@yahoo.com.br> <20060208223956.X57882@fledge.watson.org> In-Reply-To: <20060208223956.X57882@fledge.watson.org> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit UNIFESP-Virus-Scanned: by amavisd-new at dis.epm.br Cc: net@freebsd.org Subject: Re: RELENG_6 No buffer space available [udp stream] 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: Thu, 09 Feb 2006 12:27:15 -0000 Hi Robert, Thanks for your explanation, i don't have ideas about with send() work on freebsd and linux, reading the man in linux and search per ENOBUFS, FYI --------- ENOBUFS The output queue for a network interface was full. This generally indicates that the interface has stopped sending, but may be caused by transient congestion. (Normally, this does not occur in Linux. Packets are just silently dropped when a device queue overflows.) --------- For measure network throughput you recommend netperf or iperf ? Or any other option ? Thanks Ricardo A. Reis UNIFESP Unix and Network Admin >> >> write2 failed: No buffer space available > > ENOBUFS is the error returned when a process is sending packets faster > than the transmitting interface can actually transmit them. It occurs > when the interface send queue fills, and the packet is dropped. As > UDP is a lossy datagram protocol without flow control, your process > doesn't block, but it does get back an error telling it that the > packet could not be transmitted. I'm not sure how Linux behaves under > the same conditions -- it could be there is silent drop (send returns > 0, but the packet is dropped). If the application has been written > without knowing that send() can fail for UDP, it might not know how to > take that into account, and might exit/error out improperly. > > Robert N M Watson