tunneling L2 tagged traffic over IP
vas at mpeks.tomsk.su
Tue Apr 28 03:40:56 UTC 2015
Nikos Vassiliadis wrote:
> > I have two interfaces in a bridge:
> > # ifconfig bridge0
> > bridge0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
> > ether 02:d7:d7:0d:ff:00
> > inet 10.14.133.20 netmask 0xffffffc0 broadcast 10.14.133.63
> > nd6 options=9<PERFORMNUD,IFDISABLED>
> > id 00:00:00:00:00:00 priority 61440 hellotime 2 fwddelay 15
> > maxage 20 holdcnt 6 proto rstp maxaddr 2000 timeout 1200
> > root id 00:00:00:00:00:00 priority 61440 ifcost 0 port 0
> > member: vr0 flags=1c3<LEARNING,DISCOVER,AUTOEDGE,PTP,AUTOPTP>
> > ifmaxaddr 0 port 6 priority 128 path cost 200000
> > member: tap0 flags=143<LEARNING,DISCOVER,AUTOEDGE,AUTOPTP>
> > ifmaxaddr 0 port 11 priority 128 path cost 2000000
> > #
> > "tcpdump -i vr0 stp" sees incoming STP traffic while "tcpdump -i tap0 stp"
> > sees none no matter if net.link.bridge.pfil_onlyip is "1" or "0".
> > I see however some IP6, IPX (!) and CDP frames.
> STP frames are not forwarded. As well as other special frames:
> > /*
> > * Check if its a reserved multicast address, any address
> > * listed in 802.1D section 7.12.6 may not be forwarded by the
> > * bridge.
> > * This is currently 01-80-C2-00-00-00 to 01-80-C2-00-00-0F
> > */
> FreeBSD does that unconditionally. That could probably be a tunable:)
> If you have a "simple" ethernet bridge (without STP) you should
> forward STP frames. I guess a patch would be welcome!
That's from src/sys/net/if_bridge.c
Fine. Maybe there are other ways to tunnel Ethernet without relying on
Besides, I also need to tunnel 802.1q tagged frames, so if_bridge is
Victor Sudakov, VAS4-RIPE, VAS47-RIPN
sip:sudakov at sibptus.tomsk.ru
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