Hi all,
I am having some problems getting a Xen bridge up in Ubuntu precise with Xen.
I created a first bridge on eth1 with no problems, but the exact same process for eth2 yields the following problems:

auto xenbr1
iface xenbr1inet manual
bridge_ports eth1
bridge_fd 9
bridge_hello 2
bridge_maxage 12
bridge_stp off

auto xenbr2
iface xenbr2 inet manual
bridge_ports eth2
bridge_fd 9
bridge_hello 2
bridge_maxage 12
bridge_stp off

ifup xenbr2
Waiting for xenbr2 to get ready (MAXWAIT is 20 seconds).
ssh stop/waiting
ssh start/running, process 10377
(Takes quite a while)

dmesg | tail
[108513.254296] device eth2 entered promiscuous mode
[108513.390125] IPv6: ADDRCONF(NETDEV_UP): eth2: link is not ready
[108513.410895] IPv6: ADDRCONF(NETDEV_UP): xenbr2: link is not ready

ifconfig eth2
eth2 Link encap:Ethernet direcciónHW 00:26:b9:46:61:1d

Paquetes RX:0 errores:0 perdidos:0 overruns:0 frame:0
Paquetes TX:0 errores:0 perdidos:0 overruns:0 carrier:0
colisiones:0 long.colaTX:1000
Bytes RX:0 (0.0 B) TX bytes:0 (0.0 B)

I have tried adding the following lines to sysctl:

net.ipv6.conf.all.disable_ipv6 = 1
net.ipv6.conf.default.disable_ipv6 = 1
net.ipv6.conf.lo.disable_ipv6 = 1

No joy there...

Does anyone know where I am messing up?
Cheers for the help!

  • Did you plug in a network cable? Jul 4, 2013 at 20:49

2 Answers 2


It was a driver issue.
Compiled ethernet drivers from compat-drivers and it worked.


Apparently that switch does not work (with today kernels). You have to disable ipv6 for every single interface individually.

  • net.ipv6.conf.default.disable_ipv6 = 1<br> net.ipv6.conf.lo.disable_ipv6 = 1<br> net.ipv6.conf.eth2.disable_ipv6 = 1<br> No joy there either Jul 4, 2013 at 18:14

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