From owner-freebsd-net@FreeBSD.ORG Tue Jul 1 15:12:48 2003 Return-Path: Delivered-To: freebsd-net@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id D5A9E37B401 for ; Tue, 1 Jul 2003 15:12:48 -0700 (PDT) Received: from rwcrmhc12.comcast.net (rwcrmhc12.comcast.net [216.148.227.85]) by mx1.FreeBSD.org (Postfix) with ESMTP id 262EC43F75 for ; Tue, 1 Jul 2003 15:12:48 -0700 (PDT) (envelope-from julian@elischer.org) Received: from interjet.elischer.org ([12.233.125.100]) by attbi.com (rwcrmhc12) with ESMTP id <2003070122124601400mdcbke>; Tue, 1 Jul 2003 22:12:46 +0000 Received: from localhost (localhost.elischer.org [127.0.0.1]) by InterJet.elischer.org (8.9.1a/8.9.1) with ESMTP id PAA61892; Tue, 1 Jul 2003 15:12:44 -0700 (PDT) Date: Tue, 1 Jul 2003 15:12:43 -0700 (PDT) From: Julian Elischer To: Matthew Grooms In-Reply-To: <200307012146.h61LkXOW001888@hole.shrew.net> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII cc: "freebsd-net@freebsd.org" Subject: Re: broadcast udp packets ... 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: Tue, 01 Jul 2003 22:12:49 -0000 you can use netgraph to make a "virtual bridge" see /usr/share/examples/netgraph for an example of a single bridge. attach one of the bridge hooks on each site to an ng_socket node that has made a udp vpn.. see the vpn example for that.. by combining both the bridge and vpn examples you can hook the two sites together in a bridged manner. On Tue, 1 Jul 2003, Matthew Grooms wrote: > Well, > > Ok, sounds stupid right, well here is a bit of background. My friend and > I have an IPSEC tunnel in between our two private networks connected by BSD > firewalls w/ cable modems. Without going into too much detail, certain > programs ( win32 games ) use all-routes broadcasts to advertise the info > pertaining to the workstaion hosting a particular game. After much searching, > I could find no mechanism in FreeBSD that would allow me to pass these > broadcasts from a private network, across the IPSEC tunnel and to the distant > private network. ( tried all sorts of nat and bridging configurations ) > > As a result, I decided to write a small relay daemon that used bpf to > pick up the broadcast messages from the local private network, forward them > to a peer that in turn drops it on to the distant private network. ( I know, > its a lot of work to play a game but it sounded like a fun project ) In any > case, I have most of it working well but am getting loops when the bpf dropps > the packet on the wire at the far end. It reads the packet in after writing > it out and forwards it back to the originating relay partner, just like a > really bad pong game. Setting BIOCSSEESENT on the fd does not seem to do the > trick. Any Ideas? > > In any case, I wrote a quick little program to generate a broadcast > message for use with testing the relay daemon ( I got tired of waiting for > bootp requests to be picked up by my cable modem as a test case ). > Unfortunately, I can never get the test program generate an all-routes > broadcast, they always come out as network directed broadcasts. > > ... If there is not a more conventional way of going about it, I guess > I will just have to generate one using the bpf. > > On 7/1/2003, "Chuck Swiger" wrote: > > >Matthew Grooms wrote: > >> Is there any way to generate a udp broadcast ( all routes > >> 255.255.255.255 ) packet using a standard sendto() without it being > >> translated into a local network broadcast? Is this just not "allowed"? > > > >Are you trying to use 255.255.255.255 to reach something not on a local > subnet? > > > >If you have multiple interfaces, a broadcast to 255.255.255.255 should go > out on > >all of them. That being said, the all-ones broadcast address means "all > local > >networks", and most routers will block such traffic from passing on in any > event. > > > >-- > >-Chuck > > > _______________________________________________ > freebsd-net@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-net > To unsubscribe, send any mail to "freebsd-net-unsubscribe@freebsd.org" >