From owner-freebsd-net@FreeBSD.ORG Mon Jan 5 04:14:25 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 A23D1106566C for ; Mon, 5 Jan 2009 04:14:25 +0000 (UTC) (envelope-from perryh@pluto.rain.com) Received: from agora.rdrop.com (agora.rdrop.com [199.26.172.34]) by mx1.freebsd.org (Postfix) with ESMTP id 7FB9C8FC08 for ; Mon, 5 Jan 2009 04:14:25 +0000 (UTC) (envelope-from perryh@pluto.rain.com) Received: from agora.rdrop.com (66@localhost [127.0.0.1]) by agora.rdrop.com (8.13.1/8.12.7) with ESMTP id n054EPlc048913 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NOT) for ; Sun, 4 Jan 2009 20:14:25 -0800 (PST) (envelope-from perryh@pluto.rain.com) Received: (from uucp@localhost) by agora.rdrop.com (8.13.1/8.12.9/Submit) with UUCP id n054EPRI048912 for freebsd-net@freebsd.org; Sun, 4 Jan 2009 20:14:25 -0800 (PST) Received: from fbsd61 by pluto.rain.com (4.1/SMI-4.1-pluto-M2060407) id AA10835; Sun, 4 Jan 09 20:13:09 PST Date: Sun, 04 Jan 2009 20:15:30 -0800 From: perryh@pluto.rain.com To: freebsd-net@freebsd.org Message-Id: <49618962.WvA2bFthdzGdSO/b%perryh@pluto.rain.com> References: <495edc8b.yfwTDGtb9G/8NMur%perryh@pluto.rain.com> <20090103154232.P28770@sola.nimnet.asn.au> In-Reply-To: <20090103154232.P28770@sola.nimnet.asn.au> User-Agent: nail 11.25 7/29/05 Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Subject: (partly) SOLVED: tun0 not responding to ping 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: Mon, 05 Jan 2009 04:14:25 -0000 Ian Smith wrote: > On Fri, 2 Jan 2009, perryh@pluto.rain.com wrote: > > > Why would a local interface, reported as up in ifconfig, not respond > > to a ping of its own IP address? The tun0 reported below doesn't, ... > > $ ifconfig -a ... > > tun0: flags=8051 mtu 1412 > > inet6 fe80::2b0:d0ff:fe28:ad4f%tun0 prefixlen 64 scopeid 0x4 > > inet ZZZ.ZZZ.233.42 --> ZZZ.ZZZ.233.42 netmask 0xffffffff > > Opened by PID 24635 > > I don't know if this is relevant or not, but I've never seen a point to > point interface use the same IP address on both ends of its link before. It turns out to be normal -- or at least tolerable -- for a tun(4) interface used by vpnc to have the same IP address at both ends. It started working when I added NAT Traversal Mode cisco-udp to vpnc.conf. (Presumably not all configurations of the Cisco 3000 will need that, else it would be the default, but it seems to be correct for the one involved here.) I never did figure out why that kept the interface from responding to a ping of its own address :(