[CentOS] Setup multiple bridges for use with KVM

Kai Schaetzl maillists at conactive.com
Tue Jan 12 13:47:53 UTC 2010

Jacob Hydeman wrote on Mon, 11 Jan 2010 10:50:17 -0800:

> I've setup just the IPADDR= and NETMASK= to have different static IPs in
> different subnets and changed to the BOOTPROTO=static in each of the
> ifcfg-brX scripts.
> This hasn't fixed my issue. Perhaps it's because of the way I'm trying to
> use it (or I don't get it). Does each VM that is using a specific bridged
> device need to have the same IP subnet as that of the static brX address?

No. But you have to tell via config (I don't know how KVM does this) which 
bridge the VM is going to use. And if you want it to be reachable via two 
bridges you have to set it up for two bridges and give it two IP numbers. 
And the packet then has to come in thru the correct interface/bridge, there 
is no "bridging" between the bridges. You would need to set up some 
additional routing to work around this (probably, I'm not a routing 

Is that possibly not the case? e.g. your VMs are still setup to use only 
one bridge?


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