Bridged Networking with Xen

[Ryan Golhar]

Hi,

I've got a problem with networking guest OS'es and can't seem to track 
down the problem.  I suspect it has something to do with not using eth0 
on the host machine, rather I'm using eth1.

I have a server running RHEL 5.2 with 4 NIC ports on it.  Only 1 port, 
eth1 is active.  I've modified the /etc/xen/xend-config.xsp to use eth1 
using:

(network-script 'network-bridge netdev=eth1')
(vif-script vif-bridge)

I've created a few guest OSes (Linux and Windows) and can't get them to 
see the network.  One of the guest configurations has:

vif = [ "mac=00:16:3e:48:e3:bc,bridge=xenbr1" ]

If I run /sbin/ifconfig on the host machine, I see:

eth1      Link encap:Ethernet  HWaddr 00:1E:68:2F:5A:FF
           inet addr:10.168.128.128  Bcast:255.255.255.255 
Mask:255.255.255.0
           inet6 addr: fe80::21e:68ff:fe2f:5aff/64 Scope:Link
           UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
           RX packets:73449 errors:0 dropped:0 overruns:0 frame:0
           TX packets:36915 errors:0 dropped:0 overruns:0 carrier:0
           collisions:0 txqueuelen:0
           RX bytes:7220102 (6.8 MiB)  TX bytes:11201509 (10.6 MiB)

peth1     Link encap:Ethernet  HWaddr FE:FF:FF:FF:FF:FF
           inet6 addr: fe80::fcff:ffff:feff:ffff/64 Scope:Link
           UP BROADCAST RUNNING NOARP  MTU:1500  Metric:1
           RX packets:75063 errors:0 dropped:0 overruns:0 frame:0
           TX packets:38560 errors:0 dropped:0 overruns:0 carrier:0
           collisions:0 txqueuelen:100
           RX bytes:7286167 (6.9 MiB)  TX bytes:11360621 (10.8 MiB)
           Memory:fc5c0000-fc5e0000
vif0.1    Link encap:Ethernet  HWaddr FE:FF:FF:FF:FF:FF
           inet6 addr: fe80::fcff:ffff:feff:ffff/64 Scope:Link
           UP BROADCAST RUNNING NOARP  MTU:1500  Metric:1
           RX packets:36965 errors:0 dropped:0 overruns:0 frame:0
           TX packets:73499 errors:0 dropped:0 overruns:0 carrier:0
           collisions:0 txqueuelen:0
           RX bytes:11209801 (10.6 MiB)  TX bytes:7223402 (6.8 MiB)

vif2.0    Link encap:Ethernet  HWaddr FE:FF:FF:FF:FF:FF
           UP BROADCAST NOARP  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:32
           RX bytes:0 (0.0 b)  TX bytes:0 (0.0 b)

vif3.0    Link encap:Ethernet  HWaddr FE:FF:FF:FF:FF:FF
           UP BROADCAST NOARP  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:32
           RX bytes:0 (0.0 b)  TX bytes:0 (0.0 b)

virbr0    Link encap:Ethernet  HWaddr 00:00:00:00:00:00
           inet addr:192.168.122.1  Bcast:192.168.122.255 
Mask:255.255.255.0
           inet6 addr: fe80::200:ff:fe00:0/64 Scope:Link
           UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
           RX packets:0 errors:0 dropped:0 overruns:0 frame:0
           TX packets:27 errors:0 dropped:0 overruns:0 carrier:0
           collisions:0 txqueuelen:0
           RX bytes:0 (0.0 b)  TX bytes:8254 (8.0 KiB)

xenbr1    Link encap:Ethernet  HWaddr 42:1C:34:8A:E2:E1
           UP BROADCAST RUNNING NOARP  MTU:1500  Metric:1
           RX packets:18172 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:1412937 (1.3 MiB)  TX bytes:0 (0.0 b)

The guest OSs can't get a DHCP address.  I tried disabling iptables on 
the host OS thinking the firewall was blocking something, but that has 
not effect.

I've done this before but using eth0.  Is there anything else I need to 
change that I'm missing?

Ryan