On Tue, Mar 29, 2011 at 2:36 PM, Jiri Pirko <jpirko@xxxxxxxxxx> wrote: > Tue, Mar 29, 2011 at 06:54:58PM CEST, andy@xxxxxxxxxxxxx wrote: >>On Mon, Mar 28, 2011 at 1:54 PM, igor serebryany <igor47@xxxxxxxxxxx> wrote: >>> it appears that 802.1q tagging is broken in 2.6.38 when combined with bridging. >>> here is how to reproduce the problem: >>> >>> i set up an interface for the machine running 2.6.38 on my cisco router, and >>> assign a subnet to that interface. i am using ping from the router to do the >>> testing. i am getting all the data here with 'tcpdump -e -n' from the machine. >>> >>> i ping the machine from the router, and i see properly-tagged ARP requests >>> coming in on eth0: >>> >>> 12:12:05.052465 00:11:20:dd:81:00 > ff:ff:ff:ff:ff:ff, ethertype 802.1Q >>> (0x8100), length 64: vlan 234, p 0, ethertype ARP, Request who-has 10.0.0.206 >>> tell 10.0.0.205, length 46 >>> >>> i then create a vlan interface on the machine: >>> >>> vconfig add eth0 234 >>> ifconfig eth0.234 up >>> >>> i tcpdump the newly-created interface, and i see the arp packets appearing on >>> it, now properly untagged >>> >>> 12:14:33.549939 00:11:20:dd:81:00 > ff:ff:ff:ff:ff:ff, ethertype ARP (0x0806), >>> length 60: Request who-has 10.0.0.206 tell 10.0.0.205, length 46 >>> >>> if i assign an ip to this interface, i can see pings being exchanged on eth0.234 >>> >>> 12:17:12.681079 00:11:20:dd:81:00 > ff:ff:ff:ff:ff:ff, ethertype ARP (0x0806), >>> length 60: Request who-has 10.0.0.206 tell 10.0.0.205, length 46 >>> 12:17:12.681090 00:30:48:fd:98:d8 > 00:11:20:dd:81:00, ethertype ARP (0x0806), >>> length 42: Reply 10.0.0.206 is-at 00:30:48:fd:98:d8, length 28 >>> 12:17:14.682076 00:11:20:dd:81:00 > 00:30:48:fd:98:d8, ethertype IPv4 (0x0800), >>> length 114: 10.0.0.205 > 10.0.0.206: ICMP echo request, id 24, seq 1, length 80 >>> 12:17:14.682088 00:30:48:fd:98:d8 > 00:11:20:dd:81:00, ethertype IPv4 (0x0800), >>> length 114: 10.0.0.206 > 10.0.0.205: ICMP echo reply, id 24, seq 1, length 80 >>> >>> now, i want to assign eth0 to a bridge >>> >>> brctl addbr xenbr0 >>> ifconfig xenbr0 up >>> brctl addif xenbr0 eth0 >>> >>> i now attempt to ping the machine again. watching tcpdump on eth0.234, i don't >>> see any of my packets anymore! >>> >>> instead, if i watch xenbr0 with tcpdump, i can see the tagged packets being >>> dumped straight into xenbr0, without the vlan tags stripped out! > > Yep, that seems expected. rx_handler for bridge is earlier in rx path > than vlan processing. This is was not changed in 2.6.38. This is with us > for a long time. I plan to refuse this topo in future (not sure yet > thought) > I have no idea what version Igor was using before. Even if Igor's upgrade as not from 2.6.37, this sounds like a regression. _______________________________________________ Bridge mailing list Bridge@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/bridge
