From owner-freebsd-net@FreeBSD.ORG Thu Sep 10 17:19:09 2009 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 2DC8A106566C; Thu, 10 Sep 2009 17:19:09 +0000 (UTC) (envelope-from qing.li@bluecoat.com) Received: from whisker.bluecoat.com (whisker.bluecoat.com [216.52.23.28]) by mx1.freebsd.org (Postfix) with ESMTP id 102A58FC18; Thu, 10 Sep 2009 17:19:08 +0000 (UTC) Received: from bcs-mail03.internal.cacheflow.com ([10.2.2.95]) by whisker.bluecoat.com (8.14.2/8.14.2) with ESMTP id n8AHIsxu005141; Thu, 10 Sep 2009 10:18:55 -0700 (PDT) X-MimeOLE: Produced By Microsoft Exchange V6.5 Content-class: urn:content-classes:message MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Date: Thu, 10 Sep 2009 10:18:50 -0700 Message-ID: X-MS-Has-Attach: X-MS-TNEF-Correlator: Thread-Topic: forwarding when two rip defaults Thread-Index: AcoyMOsiJkzns5e+SA+juorPfUVlBQABsfu3 References: <20090910145626.GE23661@diehard.n-r-g.com> From: "Li, Qing" To: "Randy Bush" , "Claudio Jeker" Cc: freebsd-net@freebsd.org, qingli@freebsd.org Subject: RE: forwarding when two rip defaults 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, 10 Sep 2009 17:19:09 -0000 >> I don't want to disrupt the party but I seriously doubt that routed >> supports multipath routing. Routed's radix code is unable to handle >> multipath routes. > > maybe i am confused. but my momma told me that routing !=3D = forwarding. > > i.e. routed will receive two default routes and i hope would install > them in the fib, where RADIX_MPATH forwarding would take over. am i > wrong about what routed will do? will it choose only one to install = in > the fib? > Yes, FIB is a subset of a RIB for the most part, but I think what = Claudio=20 is referring to, is the "radix" code inside the "routed" = implementation,=20 which is incapable of storing multiple routes to the same destination. = That version of the "radix" code is very similar to the original = kernel=20 "radix" code. So although "routed" may be receiving multiple = advertisements about the default routes, but because it's incapable of holding more=20 than 1 such entry in its RIB, how would it be able to install more=20 than 1 entry into the FIB ? When ECMP routes are present, the route selection for forwarding is=20 based on a simple hash key generated from the source and destination=20 IP addresses. =20 Regarding the documentation, you can get some usage text from my = original commit message. I agree more text in a man page form is warranted. At the time I did not receive much input so didn't bother to spend the cycles on more formal writeup.=20 http://svn.freebsd.org/viewvc/base?view=3Drevision&revision=3D178167 http://svn.freebsd.org/viewvc/base?view=3Drevision&revision=3D178168 -- Qing