From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jarek Poplawski Subject: Re: IP-less bridge as a martian source Date: Wed, 22 Oct 2008 21:10:27 +0200 Message-ID: <48FF7AA3.50408@gmail.com> References: <87tzb6nodj.fsf@tac.ki.iif.hu> <87wsg0wu78.fsf@tac.ki.iif.hu> <48FF614C.7020507@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org To: Ferenc Wagner Return-path: Received: from ey-out-2122.google.com ([74.125.78.24]:26354 "EHLO ey-out-2122.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752497AbYJVTJN (ORCPT ); Wed, 22 Oct 2008 15:09:13 -0400 Received: by ey-out-2122.google.com with SMTP id 6so1036362eyi.37 for ; Wed, 22 Oct 2008 12:09:11 -0700 (PDT) In-Reply-To: <48FF614C.7020507@gmail.com> Sender: netdev-owner@vger.kernel.org List-ID: Jarek Poplawski wrote, On 10/22/2008 07:22 PM: > Ferenc Wagner wrote, On 10/22/2008 05:00 PM: > >> Ferenc Wagner writes: >> >>> I expected an IP-less bridge interface to pick up no IP packets, but >>> apparently this isn't the case: broadcast packets with destination >>> address 255.255.255.255 are reported as martians by the 2.6.18 >>> kernel, which I find counterintuitive (I know 2.6.18 is rather old, >>> but that's the one supported by Xen). >>> >>> 1. Is this the expected behaviour? > > > I think so, and this thread pertains to something similar: > http://marc.info/?l=linux-netdev&m=122456602708727&w=2 Sorry! I didn't check this before writing. This: 1941 static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr, 1942 u8 tos, struct net_device *dev) 1943 { ... 1963 /* IP on this device is disabled. */ 1964 1965 if (!in_dev) 1966 goto out; 1967 1968 /* Check for the most weird martians, which can be not detected 1969 by fib_lookup. 1970 */ means something else, so with IP disabled you shouldn't have any martians! (And this is old code.) Jarek P.