From owner-freebsd-questions@FreeBSD.ORG Wed Feb 13 21:55:15 2013 Return-Path: Delivered-To: questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by hub.freebsd.org (Postfix) with ESMTP id DEE68C70 for ; Wed, 13 Feb 2013 21:55:15 +0000 (UTC) (envelope-from cswiger@mac.com) Received: from nk11p00mm-asmtp005.mac.com (nk11p00mm-asmtp005.mac.com [17.158.161.4]) by mx1.freebsd.org (Postfix) with ESMTP id B488A1D6 for ; Wed, 13 Feb 2013 21:55:15 +0000 (UTC) Received: from cswiger1.apple.com ([17.209.4.71]) by nk11p00mm-asmtp005.mac.com (Oracle Communications Messaging Server 7u4-26.01(7.0.4.26.0) 64bit (built Jul 13 2012)) with ESMTPSA id <0MI60063PFFU3140@nk11p00mm-asmtp005.mac.com> for questions@freebsd.org; Wed, 13 Feb 2013 20:55:06 +0000 (GMT) Subject: Re: Why ue0 do ARP on non local address when using static route? MIME-version: 1.0 (Apple Message framework v1085) Content-type: text/plain; charset=us-ascii From: Chuck Swiger In-reply-to: <1360787737.17354.YahooMailRC@web180906.mail.ne1.yahoo.com> Date: Wed, 13 Feb 2013 12:55:05 -0800 Content-transfer-encoding: quoted-printable Message-id: <4A4F390A-3F42-41ED-9D19-EB4CE20DB148@mac.com> References: <1360787737.17354.YahooMailRC@web180906.mail.ne1.yahoo.com> To: Jin Guojun X-Mailer: Apple Mail (2.1085) Cc: questions freebsd X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 13 Feb 2013 21:55:15 -0000 On Feb 13, 2013, at 12:35 PM, Jin Guojun wrote: > When attached a Trendent TU2-ET100 USB Ether dongle for a second = interface, it=20 > has no problem to talk to the local network (10.234.37.0/24), but it = has problem=20 > to talk to a remote network or host (10.227.148.0/24) via eu0 = interface. > When a remote host ping this host or this host ping that remote host, = ARP=20 > request is always showing up. > A static route is set and remote host is no part of the local sub net, = why ARP=20 > is going on? You've told the interface that it can reach 10.227.148.52 via = 10.234.37.80, which is the IP ue0 was configured to use. It sends ARPOP_REQUESTS to get the = MAC address of 10.227.148.52 which is expected to be reachable. > Is any sysctl parameter can fix this problem? You can do things like use proxy-arp, or setup /etc/ethers, or NAT, or = even configure ue0 to be on the same subnet as 10.227.148.52 instead, perhaps using an = alias. Regards, --=20 -Chuck