Hello, When I use a standard Redhat kernel, it's ok. Everything's working right. That the Linux bridge configuration does not work afer I upgraded the kernel to 2.6.33.2. Why? [root@node78 ~]# cat /etc/issue Red Hat Enterprise Linux Server release 5.5 (Tikanga) Kernel \r on an \m [root@node78 ~]# uname -a Linux node78 2.6.33.2 #1 SMP Wed Apr 14 10:10:29 CST 2010 x86_64 x86_64 x86_64 GNU/Linux [root@node78 ~]# cat /etc/sysconfig/selinux # This file controls the state of SELinux on the system. # SELINUX= can take one of these three values: # enforcing - SELinux security policy is enforced. # permissive - SELinux prints warnings instead of enforcing. # disabled - SELinux is fully disabled. SELINUX=disabled # SELINUXTYPE= type of policy in use. Possible values are: # targeted - Only targeted network daemons are protected. # strict - Full SELinux protection. SELINUXTYPE=targeted [root@node78 ~]# iptables -L Chain INPUT (policy ACCEPT) target prot opt source destination Chain FORWARD (policy ACCEPT) target prot opt source destination Chain OUTPUT (policy ACCEPT) target prot opt source destination [root@node78 ~]# cat /etc/sysconfig/network-scripts/ifcfg-eth0 # Intel Corporation 80003ES2LAN Gigabit Ethernet Controller (Copper) DEVICE=eth0 HWADDR=00:15:17:11:16:18 BRIDGE=br0 NM_CONTROLLED=no ONBOOT=yes [root@node78 ~]# cat /etc/sysconfig/network-scripts/ifcfg-br0 DEVICE=br0 TYPE=Bridge BOOTPROTO=static BROADCAST=192.168.0.255 IPADDR=192.168.0.78 NETMASK=255.255.255.0 NETWORK=192.168.0.0 DELAY=0 NM_CONTROLLED=no ONBOOT=yes [root@node78 ~]#cd /usr/src/ [root@node78 ~]#tar jxf linux-2.6.33.2.tar.bz2 [root@node78 ~]#ln -s linux-2.6.33.2 linux [root@node78 ~]#cd linux [root@node78 ~]#cp /boot/config-2.6.18-164.el5 /usr/src/linux-2.6.33.2/.config [root@node78 ~]#make menuconfig (add the option "enable deprecated sysfs feathures to support old userspace tools") [root@node78 ~]#make && make modules && make modules_install && make install [root@node78 ~]# ifconfig br0 Link encap:Ethernet HWaddr 00:15:17:11:16:18 inet addr:192.168.0.78 Bcast:192.168.0.255 Mask:255.255.255.0 inet6 addr: fe80::215:17ff:fe11:1618/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:7217 errors:0 dropped:0 overruns:0 frame:0 TX packets:273 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:738606 (721.2 KiB) TX bytes:36168 (35.3 KiB) eth0 Link encap:Ethernet HWaddr 00:15:17:11:16:18 inet6 addr: fe80::215:17ff:fe11:1618/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:7490 errors:0 dropped:0 overruns:0 frame:0 TX packets:304 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:100 RX bytes:866112 (845.8 KiB) TX bytes:42312 (41.3 KiB) Memory:b8820000-b8840000 eth1 Link encap:Ethernet HWaddr 00:15:17:11:16:19 inet addr:10.0.7.78 Bcast:10.255.255.255 Mask:255.0.0.0 inet6 addr: fe80::215:17ff:fe11:1619/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:4 errors:0 dropped:0 overruns:0 frame:0 TX packets:59 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:1056 (1.0 KiB) TX bytes:10982 (10.7 KiB) Memory:b8800000-b8820000 lo Link encap:Local Loopback inet addr:127.0.0.1 Mask:255.0.0.0 inet6 addr: ::1/128 Scope:Host UP LOOPBACK RUNNING MTU:16436 Metric:1 RX packets:1831 errors:0 dropped:0 overruns:0 frame:0 TX packets:1831 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:3576260 (3.4 MiB) TX bytes:3576260 (3.4 MiB) [root@node78 ~]# ifconfig vmbr0 vmbr0: error fetching interface information: Device not found Best Regards, Frank