On 01/17/2012 02:57 PM, Jorge Fábregas wrote:
Hello everyone,
I'm learning about bridged networking and how it is applied to virtual
environments (bypassing all the automation provided by libvirtd etc) .
I have a question regarding ip configuration for the virtual bridge.
Let's say I have a host (my machine) where I want to run 3 VMs bridged
to my home network (thru eth0). I have a DHCP server running on my DSL
router, and I have dhcp enabled on my 3 VMs so they all should get a
lease from the DHCP.
As far as a I know these are the raw steps needed to accomplish this:
1- create br0
2- remove current ip address from eth0
3- enslave eth0 to br0
4- create tap devices
5- attach tap devices to br0
6- assign tap devices to every VM
As you can see I haven't assigned an ip address to the virtual bridge
(br0). Why is it that (on almost any site that I visit with this setup)
they always end up assigning an ip address to br0?
Thanks in advance!
Jorge
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virt(a)lists.fedoraproject.org
https://admin.fedoraproject.org/mailman/listinfo/virt There should be no reason to
use tap devices as the bridge device can be assigned as a network controller like so:
<interface type='bridge'>
<mac address='52:54:00:22:92:24'/>
<source bridge='br0'/>
<address type='pci' domain='0x0000' bus='0x00'
slot='0x03' function='0x0'/>
</interface>
<interface type='bridge'>
<mac address='52:54:00:7c:0c:db'/>
<source bridge='br1'/>
<address type='pci' domain='0x0000' bus='0x00'
slot='0x06' function='0x0'/>
</interface>
Using virtmanager to create the network interface would add the above tags and attributes
to the guest's config file by creating a Bridge type interface.
Assign the host's IP addresses to the brX devices:
br0 Link encap:Ethernet HWaddr BC:AE:C5:BE:07:DD
inet addr:ww.xxx.yyy.zz Bcast:ww.xxx.yyy.yy Mask:255.255.255.240
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:28384 errors:0 dropped:0 overruns:0 frame:0
TX packets:16265 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:34899139 (33.2 MiB) TX bytes:2018000 (1.9 MiB)
It would look like eth0 on the guest.
And the guest IP address to ethX:
eth0 Link encap:Ethernet HWaddr 52:54:00:1B:A4:E6
inet addr:ww.xxx.yyy.xz Bcast:ww.xxx.yyy.yy Mask:255.255.255.240
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:3291 errors:0 dropped:0 overruns:0 frame:0
TX packets:2140 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:995099 (971.7 KiB) TX bytes:414119 (404.4 KiB)
Interrupt:11
On the host ifcfg-br0:
DEVICE="br0"
TYPE="Bridge"
BOOTPROTO="none"
ONBOOT="yes"
DELAY=0
GATEWAY="ww.xxx.yyy.zz"
IPADDR="ww.xxx.yyy.zx"
NETMASK="255.255.255.240"
IPV6INIT=no
On the host ifcfg-eth0:
DEVICE="eth0"
HWADDR="00:00:00:00:00:00"
ONBOOT="yes"
BRIDGE="br0"
IPV6INIT=no
On the guest ifcfg-eth0:
DEVICE="eth0"
BOOTPROTO="none"
HWADDR="52:54:00:22:92:24"
ONBOOT="yes"
IPADDR="ww.xxx.yyy.xz"
NETMASK="255.255.255.240"
GATEWAY="ww.xxx.yyy.zx"
DNS1="ww.xxx.yyy.xx"
Emmett