Hello, Presently I am running CentOS release 5.5 (Final). I am looking to setup bridging as I would like to setup some KVM virtual hosts on my system as a test lab. I am following the the instruction at this site > http://tldp.org/HOWTO/BRIDGE-STP-HOWTO/index.html but I cannot figure out where I am going wrong and would be thankful if someone could point me in the right direction. Here is what I have done: Check bridge information with the following: > ~ $ modprobe -v bridge No issues or errors > ~ $ cat /proc/modules | grep bridge > bidge 91889 0 - Live 0xffffffff89247000 Check to ensure forwarding is turned on: > ~ $ cat /proc/sys/net/ipv4/ip_forward > 1 Checked that my interface are up and running (Was sure of this but did the check anyway): > ~ $ ifconfig > eth0 Link encap:Ethernet HWaddr 48:5B:39:2A:07:D5 > inet addr:192.168.1.100 Bcast:192.168.1.255 Mask:255.255.255.0 > inet6 addr: fe80::4a5b:39ff:fe2a:7d5/64 Scope:Link > UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 > RX packets:1059 errors:0 dropped:0 overruns:0 frame:0 > TX packets:1080 errors:0 dropped:0 overruns:0 carrier:0 > collisions:0 txqueuelen:1000 > RX bytes:454226 (443.5 KiB) TX bytes:120584 (117.7 KiB) > Interrupt:90 Base address:0x8400 > > 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:92 errors:0 dropped:0 overruns:0 frame:0 > TX packets:92 errors:0 dropped:0 overruns:0 carrier:0[Thu Nov 25 So now I begin to create the bridge form CLI as I want to make sure everything works before committing it to the config: > brctl addbr br0 > ifconfig eth0 down > ifconfig br0 192.168.1.100 up > ifconfig eth0 0.0.0.0 up > route add default gw 192.168.1.254 I check my interfaces and routing: > ~ $ ifconfig > br0 Link encap:Ethernet HWaddr 00:00:00:00:00:00 > inet addr:192.168.1.100 Bcast:192.168.1.255 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:5 errors:0 dropped:0 overruns:0 carrier:0 > collisions:0 txqueuelen:0 > RX bytes:0 (0.0 b) TX bytes:398 (398.0 b) > > eth0 Link encap:Ethernet HWaddr 48:5B:39:2A:07:D5 > inet6 addr: fe80::4a5b:39ff:fe2a:7d5/64 Scope:Link > UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 > RX packets:64662 errors:0 dropped:0 overruns:0 frame:0 > TX packets:63301 errors:0 dropped:0 overruns:0 carrier:0 > collisions:0 txqueuelen:1000 > RX bytes:17699194 (16.8 MiB) TX bytes:7958063 (7.5 MiB) > Interrupt:90 Base address:0x8400 > > 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:211 errors:0 dropped:0 overruns:0 frame:0 > TX packets:211 errors:0 dropped:0 overruns:0 carrier:0 > collisions:0 txqueuelen:0 > RX bytes:17346 (16.9 KiB) TX bytes:17346 (16.9 KiB) > ~ $ route -n > Kernel IP routing table > Destination Gateway Genmask Flags Metric Ref Use Iface > 192.168.1.0 0.0.0.0 255.255.255.0 U 0 0 0 br0 > 0.0.0.0 192.168.1.254 0.0.0.0 UG 0 0 0 br0 Time to test if ping works: > ~ $ ping -c3 192.168.1.254 > PING 192.168.1.254 (192.168.1.254) 56(84) bytes of data. > ping: sendmsg: Operation not permitted > ping: sendmsg: Operation not permitted > ping: sendmsg: Operation not permitted > > --- 192.168.1.254 ping statistics --- > 3 packets transmitted, 0 received, 100% packet loss, time 2000ms I know the firewall is causing this issue so I stop the firewall: > ~ $ service iptables stop > Flushing firewall rules: [ OK ] > Setting chains to policy ACCEPT: nat filter [ OK ] > Unloading iptables modules: [ OK ] Time to try ping again: > ~ $ ping -c3 192.168.1.254 > PING 192.168.1.254 (192.168.1.254) 56(84) bytes of data. > From 192.168.1.100 icmp_seq=1 Destination Host Unreachable > From 192.168.1.100 icmp_seq=2 Destination Host Unreachable > From 192.168.1.100 icmp_seq=3 Destination Host Unreachable > > --- 192.168.1.254 ping statistics --- > 3 packets transmitted, 0 received, +3 errors, 100% packet loss, time 1999ms To back out all I needed to do was: > ifconfig br0 down > brctl delbr br0 > service iptables start > service netowrk restart Everything is back to normal. I cannot figure out what am I missing here? Interfaces and routing look to be setup correctly. Is there something else I need to be looking at? -- Regards Robert Linux The adventure of a life time. Linux User #296285 Get Counted http://counter.li.org/