Date: Tue, 1 Jul 2003 15:12:43 -0700 (PDT) From: Julian Elischer <julian@elischer.org> To: Matthew Grooms <mgrooms@shrew.net> Cc: "freebsd-net@freebsd.org" <freebsd-net@freebsd.org> Subject: Re: broadcast udp packets ... Message-ID: <Pine.BSF.4.21.0307011510190.60563-100000@InterJet.elischer.org> In-Reply-To: <200307012146.h61LkXOW001888@hole.shrew.net>
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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. > > <Sigh> ... 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" <cswiger@mac.com> 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" >
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