From owner-freebsd-net@FreeBSD.ORG Tue Mar 10 14:40:53 2015 Return-Path: Delivered-To: freebsd-net@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [8.8.178.115]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id E1D4DBE3 for ; Tue, 10 Mar 2015 14:40:53 +0000 (UTC) Received: from mail.as41113.net (mail.as41113.net [91.208.177.22]) by mx1.freebsd.org (Postfix) with ESMTP id A78AF782 for ; Tue, 10 Mar 2015 14:40:53 +0000 (UTC) Received: from [172.21.87.41] (193.98.9.212.in-addr.arpa [212.9.98.193]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: mail@m.jwh.me.uk) by mail.as41113.net (Postfix) with ESMTPSA id 3l1fH10NX6z1N22k for ; Tue, 10 Mar 2015 14:40:44 +0000 (GMT) Message-ID: <54FF0266.3080106@m.jwh.me.uk> Date: Tue, 10 Mar 2015 14:40:38 +0000 From: Joe Holden User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:31.0) Gecko/20100101 Thunderbird/31.5.0 MIME-Version: 1.0 To: freebsd-net@freebsd.org Subject: Re: FreeBSD responding with wrong receiving interface IP References: <54FE566F.5030607@winterei.se> In-Reply-To: Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 10 Mar 2015 14:40:54 -0000 On 10/03/2015 13:16, George Neville-Neil wrote: > On 10 Mar 2015, at 11:26, Paul S. wrote: > >> Hi, >> >> I've been deploying FreeBSD as customer edge routers for customers >> with sites that do not require high throughput (>1g/s). >> >> Each site has two ISPs (Mostly Telstra + Verizon/Optus), and take full >> routes via OpenBGPd and BIRD. I use next-hop self on all received routes. >> >> The FreeBSD boxes have static routes delegating the announced IP >> blocks to a L3 switch down the road. i.e: route add -net 10.100.1.0/24 >> 10.0.0.1, and then that /24 is originated via BGP to both upstreams. >> >> Things in general work fine, but I've been receiving reports of 'weird >> traceroute results' from my customers. >> >> Examples of this would be, >> >> 1 some.random.isp (...) (...) >> 2 gigabitethernet3-3.exi1.melbourne.telstra.net (203.50.77.49) 0.309 >> ms 0.284 ms 0.227 ms >> 3 bundle-ether3-100.exi-core10.melbourne.telstra.net (203.50.80.1) >> 1.966 ms 1.675 ms 1.852 ms >> 4 bundle-ether12.chw-core10.sydney.telstra.net (203.50.11.124) 16.707 >> ms 15.917 ms 16.360 ms >> 5 customer-gw.syd.ALTER.net (...) (...) >> >> This traceroute seems to claim that the packet was received over the >> Verizon gateway, which in reality it was not -- it was received >> directly over the Telstra interface, but my outbound AS-PATH towards >> some.random.isp uses Verizon. >> >> So FreeBSD replies back with the Verizon address. Another person >> having the same issue (mostly, but on OpenBSD) can be found at >> http://openbsd.7691.n7.nabble.com/BGP-responding-with-wrong-IP-address-td90264.html >> >> >> I would love to know if there's a way to fix this, or if I've missed >> something, or if there's something wrong in the way I set it up. >> >> Thank you for taking the time to read. > > I wonder if we could see some routing tables? That might help. > > Best, > George sysctl net.inet.icmp.reply_from_interface=1 will probably do what you expect.