From owner-freebsd-net@FreeBSD.ORG Wed May 22 15:48:42 2013 Return-Path: Delivered-To: freebsd-net@freebsd.org Received: from mx1.freebsd.org (mx1.FreeBSD.org [8.8.178.115]) by hub.freebsd.org (Postfix) with ESMTP id CDEDA5A4 for ; Wed, 22 May 2013 15:48:42 +0000 (UTC) (envelope-from kudzu@tenebras.com) Received: from mail-oa0-f50.google.com (mail-oa0-f50.google.com [209.85.219.50]) by mx1.freebsd.org (Postfix) with ESMTP id 9E849F27 for ; Wed, 22 May 2013 15:48:42 +0000 (UTC) Received: by mail-oa0-f50.google.com with SMTP id l20so2891424oag.9 for ; Wed, 22 May 2013 08:48:36 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type:x-gm-message-state; bh=cnCvfT/JDI4ke8/qj37TtGgjVcY1yqpZ4vGE+gGFlw0=; b=ORd2Hq/EM1nMnkrMIOaP69DVbQhqfckV8tvMHg2PecHhxUTxGZu4WUFyMud35YZz4j sKcMIQY8jr4FeUTCLt5O7DBclcHEtHmQko643E0PYszWd+qDJs5CHtRLU5xKVkZRNHr4 DSIU8irquJpzRh9xnbaibGgx4MgKN7MI1JmYhx8NYDMQXzVK+oB8zXjVv0rAPAa5IbX+ G7nU/8l8W0eK4IJWVDLXNpriaogBAyYDKZaTKQglZzprf+XJABHEageNgcV7FUP7HKxw Pctys0g0MGPxHob/Q957LGKq+Q1f58FbxbhS3P2VY+uW/aNjvxiXq8a+TnRyvmlc9LZZ aJrg== MIME-Version: 1.0 X-Received: by 10.60.142.103 with SMTP id rv7mr5302068oeb.34.1369237716488; Wed, 22 May 2013 08:48:36 -0700 (PDT) Received: by 10.60.35.132 with HTTP; Wed, 22 May 2013 08:48:36 -0700 (PDT) In-Reply-To: <20130522153905.GP887@wiggum> References: <20130522153905.GP887@wiggum> Date: Wed, 22 May 2013 08:48:36 -0700 Message-ID: Subject: Re: GRE and BPF From: Michael Sierchio To: "freebsd-net@freebsd.org" X-Gm-Message-State: ALoCoQlBBvG7LUZJslGbRMud02b392V22EpxhX6mWqm9DoPisoWo6LcN9z3JqOaB0McirTwCjQK4 Content-Type: text/plain; charset=ISO-8859-1 X-Content-Filtered-By: Mailman/MimeDel 2.1.14 X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 22 May 2013 15:48:42 -0000 On Wed, May 22, 2013 at 8:39 AM, Brian Hechinger wrote: > Hello all, > > I've been having some trouble with a GRE tunnel. Specifically with > non-IP traffic (DECnet, in this case) and BPF. > > I can see the GRE packets containing the DECnet packets coming over the > physical interface but when I do a tcpdump of bge0 I never see them. > > This is an issue because the program I want to use will be using pcap to > pull packets off of the bge0 interface. > > I can get IP packets off of the bge0 interface with tcpdump, however. > > Is this just never going to work or am I missing something here? > > What does ifconfig report for the MTU of the gre interface? Does it match the Cisco? Is grekey set? Do you have a route to the network that is encapsulated on the other side? is net.inet.ip.forwarding set to 1? - M