[libvirt-users] TCP Tunnel Info

[bancfc at openmailbox.org]

libvirt-users at redhat.com

TCP Tunnel Info

I've been looking at the TCP Tunnel network feature as a potential 
replacement for the extra private internal networking configuration 
file.

Usecase: This network is supposed to go from VM1 to VM2 without DHCP, 
DNS or any incoming/outgoing connections to the host or outside world 
possible.

https://libvirt.org/formatdomain.html#elementsNICSTCP

* To make sure I understand, adding the TCP Tunnel setting for both VMs 
1 and 2 is enough to do what I need? (force them to exclusively 
communicate without the need for adding a new network as typically 
done).

* If another set of VMs 3 and 4 are running and connected to each other 
but I want to make sure they cannot connect to VMs 1 and 2, what source 
addresses should be used to isolate these 2 networks? Do you follow CIDR 
rules?

* For example if the chosen source address is 10.152.152.11 for VMs 1 
and 2 what should the other network have?

* Going more complicated. Can one VM participate in two separate TCP 
Tunnel networks while keeping them isolated? Topology: VM1(virtual NIC1) 
<-> VM2  | VM1(virtual NIC2) <-> VM3

VM2 and 3 can only talk to VM1 but not to each other in this example.

* Offtopic: Do your answers similarly apply for using the other 
Multicast and UDP options too?

I can explain better if I'm not making any sense.