Network management architecture

Architecture illustration

The diagrams below illustrate some of the network configurations enabled by the libvirt networking APIs

VLAN 1. This virtual network has connectivity to LAN 2 with traffic forwarded and NATed.
VLAN 2. This virtual network is completely isolated from any physical LAN.
Guest A. The first network interface is bridged to the physical LAN 1. The second interface is connected to a virtual network VLAN 1.
Guest B. The first network interface is connected to a virtual network VLAN 1, giving it limited NAT based connectivity to LAN2. It has a second network interface connected to VLAN 2. It acts a router allowing limited traffic between the two VLANs, thus giving Guest C connectivity to the physical LAN 2.
Guest C. The only network interface is connected to a virtual network VLAN 2. It has no direct connectivity to a physical LAN, relying on Guest B to route traffic on its behalf.

Logical network architecture

Physical network architecture