[libvirt-users] Problems setting up bridge

[Alex]

Hi,
I have a fc14 box with two interfaces that I'm having some difficulty
setting up a bridge properly. I have a few kvm guests set up and
running, but I've switched from using NetworkManager to using standard
networking with a bridge. I've modified the ifcfg-eth0 and created
ifcfg-br0 as per the standard documentation, but I think I'm having
routing problems. This is what the network looks like:

[root at fc14 ~]# route
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
68.195.XXX.40   *               255.255.255.248 U     0      0        0 br0
192.168.1.0     *               255.255.255.0   U     0      0        0 eth1
192.168.125.0   *               255.255.255.0   U     0      0        0 virbr0
link-local      *               255.255.0.0     U     1003   0        0 eth1
link-local      *               255.255.0.0     U     1004   0        0 br0
default         ool-44c3c129.st 0.0.0.0         UG    0      0        0 br0

br0       Link encap:Ethernet  HWaddr 40:61:86:4E:84:09
          inet addr:68.195.XXX.42  Bcast:68.195.XXX.47  Mask:255.255.255.248
          inet6 addr: fe80::a0e7:ecff:fefd:340a/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:3883 errors:0 dropped:0 overruns:0 frame:0
          TX packets:3579 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:1818327 (1.7 MiB)  TX bytes:590720 (576.8 KiB)

eth0      Link encap:Ethernet  HWaddr 40:61:86:4E:84:09
          inet6 addr: fe80::4261:86ff:fe4e:8409/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:3891 errors:0 dropped:0 overruns:0 frame:0
          TX packets:3551 errors:0 dropped:0 overruns:0 carrier:1
          collisions:0 txqueuelen:1000
          RX bytes:1873169 (1.7 MiB)  TX bytes:588302 (574.5 KiB)
          Interrupt:42

eth1      Link encap:Ethernet  HWaddr 00:0E:0C:3B:36:F4
          inet addr:192.168.1.1  Bcast:192.168.1.255  Mask:255.255.255.0
          inet6 addr: fe80::20e:cff:fe3b:36f4/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:7622 errors:0 dropped:0 overruns:0 frame:0
          TX packets:6936 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:1062687 (1.0 MiB)  TX bytes:4304984 (4.1 MiB)

virbr0    Link encap:Ethernet  HWaddr E6:ED:D2:6E:58:5C
          inet addr:192.168.125.1  Bcast:192.168.125.255  Mask:255.255.255.0
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:0 (0.0 b)  TX bytes:0 (0.0 b)

vnet0     Link encap:Ethernet  HWaddr FE:54:00:67:2C:4C
          inet6 addr: fe80::fc54:ff:fe67:2c4c/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:5 errors:0 dropped:0 overruns:0 frame:0
          TX packets:391 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:500
          RX bytes:300 (300.0 b)  TX bytes:23358 (22.8 KiB)

I've left out the loopback for simplicity. The problem is that I can't
reach the br0 device from a server on the eth1 device (the 192.168.
network).

Is this a routing issue? Should I also add the eth1 device to the
bridge? If so, how would I do that?

Also, can you explain under what circumstances a tun device would be
used? Does that have any relation to bridging?

Thanks,
Alex