On Tue, Jul 21, 2009 at 4:52 PM, Michael Tremer<michael.tremer@xxxxxxxxxx> wrote: > Hello everybody, > I got a weird problem but don't know if it is expected to work. > > brctl addbr br0 > vconfig add eth0 30 > brctl addif br0 eth0.30 > > Until here, everythink works well... I can access the VLAN with id 30. > But when I run the following: > > brctl addif br0 eth0 I'm sure someone will step in and correct me if I'm wrong. You are wanting to treat packets with no VLAN header the same as those tagged in VLAN 30. But "eth0" does not mean "packets with no VLAN header", it means *ALL* packets which arrive through eth0. This packet stream is passed through VLAN processing and distribution is done, dealing the payloads (now without the VLAN header) to the virtual interfaces. Imagine if the bridge module blindly did what you asked. Then every packet in eth0.30 would have a VLAN header added and placed into eth0 for transmission. Because eth0 is part of a bridge, it is eligible for transmission through each port of the bridge, so it is copied to eth0.30. Now the VLAN module processes it out, adding a VLAN header and placing it into eth0. The snowball effect would quickly swamp the network. So bridge ignores the virtual slave interfaces if you brctl addif the master device. I don't think Linux VLAN support provides a way to separate packets with _no_ VLAN header onto a virtual interface, but that surely sounds useful. There'd be problems with nested VLANs though. In a system with two layer nesting, is a packet that arrives with only one tag treated as missing the inner tag or the outer one? > > Then, I can't access the VLAN any more but the untagged LAN. > But instead of adding eth0: > > vconfig add eth0 40 > brctl addif br0 eth0.40 > > It works. > > It would be nice if you can me give a short advice... > Is it not possible to bridge an untagged LAN with a tagged VLAN or > is this a bug? > > Sincerely, > > Michael > > Kernel 2.6.29, brctl 1.4 > > _______________________________________________ > Bridge mailing list > Bridge@xxxxxxxxxxxxxxxxxxxxxxxxxx > https://lists.linux-foundation.org/mailman/listinfo/bridge > _______________________________________________ Bridge mailing list Bridge@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/bridge
