From owner-freebsd-net@FreeBSD.ORG Mon May 25 08:30:01 2015 Return-Path: Delivered-To: freebsd-net@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id A2B482CE for ; Mon, 25 May 2015 08:30:01 +0000 (UTC) (envelope-from mark@tuxis.nl) Received: from alcyone.saas.tuxis.net (alcyone.saas.tuxis.net [31.3.111.19]) (using TLSv1.1 with cipher ECDHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 0A218AEB for ; Mon, 25 May 2015 08:29:59 +0000 (UTC) (envelope-from mark@tuxis.nl) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=tuxis.nl; s=mail; h=from:subject:date:message-id:to:cc:mime-version:content-type: content-transfer-encoding:in-reply-to:references; bh=rNna/EAPZ9LOe/IBbTwzHzh2TRXYhkjJCfV9fxzgcc0=; b=Kbpy6XXK+q734YsJvTOioh/XK9jVYr+M2UaLYxOMMe6r4Bno6aq/c2yhJnLfw+9VwNE1BsDVq/3VZ hIhckx/oEeoLOAaYyosSLYpgxqJ5uem03PMi8wWISaGqBC7uZZIUNOH7gKdoBQsahwaVO46TB+Fr24 mTfZ1ENVN5nvFrQdcU8DE0dsONYTuUb2asXHelZ/XpnRhgIw9PNgnKrjx1IVWbzyMw5TDZUCm2chv9 47lrf1zGQaQ1IIVowqtsglUxqjgvSADc6325J3+hYhJeq4fmkGhPRX8NzBGXqaS6QCTX2JMP38PSHt 1/nJDaVZLDHabKJay3fNKIT+z2EWLNw== X-Footer: dHV4aXMubmw= Received: from [193.217.21.132] ([193.217.21.132]) by alcyone.saas.tuxis.net (Kerio Connect 8.5.0); Mon, 25 May 2015 09:59:45 +0200 From: "Mark Schouten" Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: quoted-printable Subject: Re: FreeBSD 10.1-REL - network unaccessible after high traffic References: <5562D0F3.4070408@field.hu> Mime-Version: 1.0 (1.0) In-Reply-To: <5562D0F3.4070408@field.hu> Message-Id: <13CD4CDB-1744-4E2F-8FD7-BFE2365121F3@tuxis.nl> Date: Mon, 25 May 2015 09:59:45 +0200 To: Cs Cc: "freebsd-net@freebsd.org" X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 25 May 2015 08:30:01 -0000 Try lowering your mtu to 1500, that worked miracles for me.. --=20 Mark Schouten Tuxis Internet Engineering mark@tuxis.nl / 0318 200208 > On 25 May 2015, at 09:36, "Cs" wrote: >=20 > Hi all, >=20 > I have two FreeBSd 10.1-RELEASE servers connected to each other. They were= connected via cross link, but they are connected to a cisco switch now (the= problem was the same with cross link too). When transferring huge files (50= -500GB backup files) via Gigabit (it is important!) the network randomly die= s. The backup runs every day/week and sometimes the connection is ok for mon= ths sometimes it happens twice a week. When the network dies I can log in to= the server via IPMI and use the console everything is OK, but can't send an= ything out on the network. ifconfig em0 down/up doesn't help nor netif resta= rt. The problem never occured when I used 100Mbit connection between them, b= ut it was 3com NIC (xl), gigabit adapter is Intel (em0). When I limit the tr= ansfer rate (rsync bandwith limit or ipfw pipe) the problem is much more rar= e. >=20 > I tried to set these tuning parameters on both servers with different buff= er size but nothing helped: >=20 > # cat /etc/sysctl.conf > security.bsd.see_other_uids=3D0 > net.inet.tcp.recvspace=3D512000 > net.route.netisr_maxqlen=3D2048 > kern.ipc.nmbclusters=3D1310720 > net.inet.tcp.sendbuf_max=3D16777216 > net.inet.tcp.recvbuf_max=3D16777216 > kern.ipc.soacceptqueue=3D32768 >=20 > # cat /boot/loader.conf > geom_mirror_load=3D"YES" # RAID1 disk driver (see gmirror(8)) > ipfw_load=3D"YES" > net.inet.ip.fw.default_to_accept=3D1 > kern.maxusers=3D4096 > accf_data_load=3D"YES" >=20 > The duplex settings are identical on both servers. >=20 > Server A: > em1: flags=3D8843 metric 0 mtu 900= 0 > options=3D4219b=20 > ether 00:25:90:24:52:66 > inet x.x.x.x netmask 0xfffffe00 broadcast x.x.x.x > nd6 options=3D29 > media: Ethernet autoselect (1000baseT ) > status: active >=20 > Server B: > em0: flags=3D8843 metric 0 mtu 900= 0 > options=3D4219b=20 > ether 00:30:48:dd:fe:3e > inet x.x.x.x netmask 0xfffffe00 broadcast x.x.x.x > nd6 options=3D29 > media: Ethernet autoselect (1000baseT ) > status: active >=20 > Today I tried to set mtu to 9000 but in tcpdump I see that during scp it i= s still 1500: > x.x.x.x.222 > x.x.x.x.37612: Flags [.], cksum 0xb6ee (incorrect -> 0xda= 6f), seq 35749, ack 113701596, win 7986, options [nop,nop,TS val 3103966325 e= cr 853712893], length 0 > 09:27:33.912354 IP (tos 0x8, ttl 64, id 1028, offset 0, flags [DF], proto T= CP (6), length 1500) > 09:27:33.912358 IP (tos 0x8, ttl 64, id 1029, offset 0, flags [DF], proto T= CP (6), length 1500) >=20 >=20 > Any ideas? Thanks guys! > _______________________________________________ > 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"