how do I start the xen network

Hi all,

I installed the xen kernel (2.6.18-1.2849.fc6xen) and it works except I 
no longer have network connection.
When I boot kernel 2.6.18-1.2849.fc6, the DHCP server provides an IP 
address and everything works just fine.
I use the default bridged network and the default config-xen.sxp
I haven't created any domU, yet.

The question is, how do I start the network? xend is running.

Here are the outputs of ifconfig and brctl show xenbr0:

eth0      Link encap:Ethernet  HWaddr 00:15:C5:BB:43:ED 
         UP BROADCAST RUNNING MULTICAST  MTU:0  Metric:1
         RX packets:13 errors:0 dropped:0 overruns:0 frame:0
         TX packets:4 errors:0 dropped:0 overruns:0 carrier:0
         collisions:0 txqueuelen:0
         RX bytes:2944 (2.8 KiB)  TX bytes:828 (828.0 b)

lo        Link encap:Local Loopback 
         inet addr:127.0.0.1  Mask:255.0.0.0
         UP LOOPBACK RUNNING  MTU:16436  Metric:1
         RX packets:17 errors:0 dropped:0 overruns:0 frame:0
         TX packets:17 errors:0 dropped:0 overruns:0 carrier:0
         collisions:0 txqueuelen:0
         RX bytes:1274 (1.2 KiB)  TX bytes:1274 (1.2 KiB)

peth0     Link encap:Ethernet  HWaddr FE:FF:FF:FF:FF:FF 
         UP BROADCAST RUNNING NOARP  MTU:1500  Metric:1
         RX packets:13 errors:0 dropped:0 overruns:0 frame:0
         TX packets:3 errors:0 dropped:0 overruns:0 carrier:0
         collisions:0 txqueuelen:1000
         RX bytes:2996 (2.9 KiB)  TX bytes:786 (786.0 b)
         Interrupt:18

vif0.0    Link encap:Ethernet  HWaddr FE:FF:FF:FF:FF:FF 
         UP BROADCAST RUNNING NOARP  MTU:1500  Metric:1
         RX packets:4 errors:0 dropped:0 overruns:0 frame:0
         TX packets:13 errors:0 dropped:0 overruns:0 carrier:0
         collisions:0 txqueuelen:0
         RX bytes:828 (828.0 b)  TX bytes:2944 (2.8 KiB)

xenbr0    Link encap:Ethernet  HWaddr FE:FF:FF:FF:FF:FF 
         UP BROADCAST RUNNING NOARP  MTU:1500  Metric:1
         RX packets:17 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:3534 (3.4 KiB)  TX bytes:0 (0.0 b)
---------------------------------------------------------------------------------
bridge name     bridge id               STP enabled     interfaces
xenbr0          8000.feffffffffff       no              peth0
                                                                  vif0.0
---------------------------------------------------------------------------------
Any comment is appreciated!

Laszlo