CentOS 6.2 Bridge Setup for KVM
- by Gaia
I'm trying to set up bridged networking with KVM on CentOS 6.2 to no avail. There are plenty of docs and tutorials about it, but they all seem to conflict or don't provide info specific enough to my situation. I just don't get it.
I access the host via public IP "xxx.xxx.128.58". All other available IPs (/29) should be bridged and made available to the only KVM guest (running a public facing LAMP stack) that will be setup on this machine.
The amazingly unhelpful NOC people assigned the extra IPs to eth1. Is
this correct?
Should br0 bridge to eth0 or eth1?
How do I set this up?
Here is the relevant info:
eth0 Link encap:Ethernet HWaddr 00:25:90:68:FE:BC
inet6 addr: fe80::225:90ff:fe68:febc/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:763 errors:0 dropped:0 overruns:0 frame:0
TX packets:8 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:550811 (537.9 KiB) TX bytes:648 (648.0 b)
Memory:fb980000-fba00000
eth1 Link encap:Ethernet HWaddr 00:25:90:68:FE:BD
inet addr:xxx.xxx.128.58 Bcast:xxx.xxx.128.63 Mask:255.255.255.248
inet6 addr: fe80::225:90ff:fe68:febd/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:1806 errors:0 dropped:0 overruns:0 frame:0
TX packets:1505 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:133166 (130.0 KiB) TX bytes:106070 (103.5 KiB)
Memory:fb900000-fb980000
eth1:0 Link encap:Ethernet HWaddr 00:25:90:68:FE:BD
inet addr:xxx.xxx.128.59 Bcast:xxx.xxx.128.63 Mask:255.255.255.248
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
Memory:fb900000-fb980000
eth1:1 Link encap:Ethernet HWaddr 00:25:90:68:FE:BD
inet addr:xxx.xxx.128.60 Bcast:xxx.xxx.128.63 Mask:255.255.255.248
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
Memory:fb900000-fb980000
eth1:2 Link encap:Ethernet HWaddr 00:25:90:68:FE:BD
inet addr:xxx.xxx.128.61 Bcast:xxx.xxx.128.63 Mask:255.255.255.248
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
Memory:fb900000-fb980000
eth1:3 Link encap:Ethernet HWaddr 00:25:90:68:FE:BD
inet addr:xxx.xxx.128.62 Bcast:xxx.xxx.128.63 Mask:255.255.255.248
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
Memory:fb900000-fb980000
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: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)
virbr0 Link encap:Ethernet HWaddr 52:54:00:62:55:68
inet addr:192.168.122.1 Bcast:192.168.122.255 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)
> cat /etc/sysconfig/network
NETWORKING=yes
HOSTNAME=XXXX.domain.com
> brctl show
bridge name bridge id STP enabled interfaces
br0 8000.00259068febc no eth0
virbr0 8000.525400625568 yes virbr0-nic
> ls -fl | grep ifcfg
-rw-r--r-- 1 root root 198 Jun 7 10:58 ifcfg-eth0
-rw-r--r--. 1 root root 254 Oct 7 2011 ifcfg-lo
-rw-r--r-- 1 root root 77 Jun 6 18:51 ifcfg-eth1-range0
-rw-r--r-- 1 root root 168 Jun 6 18:50 ifcfg-eth1
> cat ifcfg-eth0
DEVICE="eth0"
BOOTPROTO="static"
BRIDGE="br0"
HWADDR="00:25:90:68:FE:BC"
IPV6INIT="yes"
MTU="1500"
NM_CONTROLLED="yes"
ONBOOT="yes"
TYPE="Ethernet"
IPADDR="yyy.yyy.216.131"
NETMASK="255.255.255.128"
> cat ifcfg-eth1
DEVICE="eth1"
HWADDR="00:25:90:68:FE:BD"
NM_CONTROLLED="yes"
ONBOOT="yes"
BOOTPROTO="static"
IPADDR="xxx.xxx.128.58"
NETMASK="255.255.255.248"
GATEWAY="xxx.xxx.128.57"
> cat ifcfg-eth1-range0
IPADDR_START="xxx.xxx.128.59"
IPADDR_END="xxx.xxx.128.62"
CLONENUM_START="0"
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
xxx.xxx.128.56 * 255.255.255.248 U 0 0 0 eth1
192.168.122.0 * 255.255.255.0 U 0 0 0 virbr0
link-local * 255.255.0.0 U 1003 0 0 eth1
default xxx.xxx.128.57 0.0.0.0 UG 0 0 0 eth1