From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Dumazet Subject: Re: Problems Receiving UDP Broadcasts on Some Versions of Linux Date: Mon, 25 Jan 2010 09:10:14 +0100 Message-ID: <4B5D51E6.5090601@gmail.com> References: <20100125072749.GG21419@analytic.cynic.net> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE To: Curt Sampson , linux-kernel@vger.kernel.org, Linux Netdev List Return-path: In-Reply-To: <20100125072749.GG21419@analytic.cynic.net> Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org Le 25/01/2010 08:27, Curt Sampson a =E9crit : > I'm posting this here because it smells as if it may be something > a where a kernel network code developer might just say, "oh yeah, > obviously your problem is this." >=20 > I'm not subscribed to this list, so please cc me on any replies. (The > Mail-followup-to header may do this automatically for you.) >=20 > The short summary is that on two very similar servers on the same > network, an application that listens for broadcast UDP packets on a > given port works fine on the Ubuntu 8.04/Linux 2.6.24-26-server box b= ut > does not receive the packets on the Ubuntu 9.04/Linux 2.6.28-17-serve= r > box. I have confirmed that tcpdump sees identical packets being recei= ved > on both hosts. >=20 > Did something change between these two kernel revisions that I need t= o > listen differently? >=20 > Full details, including sample code, are available at: >=20 > http://stackoverflow.com/questions/2130563/udp-broadcast-reception-= problems-with-ubuntu-9-04-but-not-8-04 >=20 > Thanks for any help you can give me. Even if you're not sure, but hav= e > clues I should consider following up, feel free to e-mail me. I'm > also happy to take pointers to kernel code I should read, if there's > enlightenment there. >=20 > cjs Hi Curt Could you post a sample of tcpdump trafic you receive on the 9.04 host,= and your network config ? "ifconfig -a"