From owner-freebsd-stable@FreeBSD.ORG Tue Aug 12 15:50:21 2008 Return-Path: Delivered-To: stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id E9A141065674 for ; Tue, 12 Aug 2008 15:50:21 +0000 (UTC) (envelope-from thompsa@FreeBSD.org) Received: from pele.citylink.co.nz (pele.citylink.co.nz [202.8.44.226]) by mx1.freebsd.org (Postfix) with ESMTP id AE49D8FC13 for ; Tue, 12 Aug 2008 15:50:21 +0000 (UTC) (envelope-from thompsa@FreeBSD.org) Received: from localhost (localhost [127.0.0.1]) by pele.citylink.co.nz (Postfix) with ESMTP id 899AA2BDAC; Wed, 13 Aug 2008 03:50:20 +1200 (NZST) X-Virus-Scanned: Debian amavisd-new at citylink.co.nz Received: from pele.citylink.co.nz ([127.0.0.1]) by localhost (pele.citylink.co.nz [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id J6+-SLHECK5N; Wed, 13 Aug 2008 03:50:16 +1200 (NZST) Received: from citylink.fud.org.nz (unknown [202.8.44.45]) by pele.citylink.co.nz (Postfix) with ESMTP; Wed, 13 Aug 2008 03:50:16 +1200 (NZST) Received: by citylink.fud.org.nz (Postfix, from userid 1001) id 60A441142C; Wed, 13 Aug 2008 03:50:16 +1200 (NZST) Date: Tue, 12 Aug 2008 08:50:16 -0700 From: Andrew Thompson To: Peter Jeremy Message-ID: <20080812155016.GB45850@citylink.fud.org.nz> References: <20080812105552.GA89695@svzserv.kemerovo.su> <20080812112430.GC64458@server.vk2pj.dyndns.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20080812112430.GC64458@server.vk2pj.dyndns.org> User-Agent: Mutt/1.5.17 (2007-11-01) Cc: stable@freebsd.org, Eugene Grosbein , Marian Hettwer Subject: Re: lagg(4) and failover X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 12 Aug 2008 15:50:22 -0000 On Tue, Aug 12, 2008 at 09:24:30PM +1000, Peter Jeremy wrote: > On 2008-Aug-12 18:55:52 +0800, Eugene Grosbein wrote: > >On Tue, Aug 12, 2008 at 12:37:15PM +0200, Marian Hettwer wrote: > > > >> I'm using lagg(4) on some of our servers and I'm just wondering how the > >> failover is implemented. > > As far as I can tell, not especially well :-(. It doesn't seem to detect > much short of layer 1 failure. In particular, shutting down the switch > port will not trigger a failover. > > >> The manpage isn't quite clear: > >> > >> failover Sends and receives traffic only through the master port. > >> If > >> the master port becomes unavailable, the next active port > >> is > >> used. The first interface added is the master port; any > >> interfaces added after that are used as failover devices. > >> > >> What is meant by "becomes unavailable"? Is it just the physical link which > >> needs to become unavailable to trigger a failover? > > It seems to be, > > >Yes. It seems you need lacp protocol described later in the manual. > > Actually, lacp and failover are used differently: lacp is primarily > used to increase the bandwidth between the host and the switch whilst > failover is used for redundancy. > > With lacp, all the physical interfaces must be connected to a single > switch. With failover, the physical interfaces will normally be > connected to different switches (so a failure in one switch will not > cause the loss of all connectivity. Actually you can use lacp in failover mode by connecting interfaces to different switches. It will only bundle an aggregation to one switch at a time but if that becomes unavailable then it will automatically choose the next switch. Andrew