[libvirt] Network Configuration question

[Remko Nolten]

Hi!

For a shared virtual hosting project with some friends we need a  
pretty specialized network configuration. Because we have virtually no  
time for experimenting (no pun intended), and the hosting organization  
has no experience with libvirt/KVM configurations they suggested to  
try and ask here.

So, this is the situation: We have a server with one physical  
connection. Each user gets one virtual machine with its own IP-address  
(we have our own ip-range). The hosting organization gives us one  
"main" address 'A' with netmask 255.255.255.0 (/24) and a default  
gateway for our host machine. Besides this we get a number of  
addresses B1, B2, etc. with netmask 255.255.255.255 (/32) and without  
a default gateway. The switch just routes the traffic to our server  
for each ip-address we own (A and Bn).

According to our hosting organization, the normal solution is to  
configure a loopback interface for each of the ip-addresses on the  
server so you can configure your software just to use one of the  
addresses. But we are not sure how this will work out in our virtual  
environment. Our intuition tells us we need to use the routing network  
forwarding mode, but when we bring the server to the data center we  
don't want to have any surprises. :)

Here at home I don't have to possibility to create similar  
circumstances as in the data center due to some restriction from my  
ISP, so I hope someone can tell me if our intuition is correct or that  
we need to use some other method.

Thanks in advance!

-- 
Remko Nolten
Tel: 		06-45600767
E-mail: 	remko at nolten.nu