From owner-freebsd-net@FreeBSD.ORG Wed Jun 9 19:45:38 2004 Return-Path: Delivered-To: freebsd-net@freebsd.org Received: by hub.freebsd.org (Postfix, from userid 618) id C165316A4D0; Wed, 9 Jun 2004 19:45:38 +0000 (GMT) In-Reply-To: <40C747D8.1030200@bazmag.hu> from Tamas MEZEI at "Jun 9, 2004 07:24:40 pm" To: tamas@bazmag.hu (Tamas MEZEI) Date: Wed, 9 Jun 2004 19:45:38 +0000 (GMT) X-Mailer: ELM [version 2.4ME+ PL54 (25)] MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Message-Id: <20040609194538.C165316A4D0@hub.freebsd.org> From: wpaul@FreeBSD.ORG (Bill Paul) cc: freebsd-net@freebsd.org Subject: Re: two nics, same network, different topics X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 09 Jun 2004 19:45:38 -0000 [...] > We're using Netramet and Nemac to get data from the flows. If the mirror > iface has an ip address, Nemac cannot "poll" (or whatever it's called it > does) data from Netramet and the bge0 card and saying something like no > response from x.x.x.3 (it's the fxp0 card). (It's kinda strange, and > kinda offtopic, but networking related.) If I say, ifconfig bge0 delete, > it works again. > > The metering card has an IP address because tcpdump would complain (no > IPv4 address) and maybe it affects it's capabilities. (I'm not so sure.) Uh... no. Whether or not the interface has an IP address does not "affect its capabilities." If all you want to do is snoop traffic via tcpdump (or something like it), you don't need an IP address on the interface. Period. Snooping traffic is done via BPF, which grabs all frames they even get anywhere near the IP layer. If you're not actually using the bge0 interface to exchange any traffic, just do ifconifg bge0 up and don't bother putting an IP address on it. You'll still be able to put the interface into promiscuous mode and monitor packets to your heart's content. Don't let the big bad tcpdump warning message scare you. -Bill -- ============================================================================= -Bill Paul (510) 749-2329 | Senior Engineer, Master of Unix-Fu wpaul@windriver.com | Wind River Systems ============================================================================= you're just BEGGING to face the moose =============================================================================