We can examine the bridge configuration to confirm that these new
interfaces were correctly attached to the network bridge by using the bridge utils:
We can see how a new virtual interface vif8.0 was attached to the bridge. This
interface is used by the domU that we created.
The following diagram shows the complete network configuration with all
the created interfaces and the attachments to the bridge, with both dom0 and
domU running.
Routed Networking
Routing is a technique that uses IP forwarding to relay network traffic from one
segment to another. In this case, dom0 in Xen acts as a conduit for the guest domains
to communicate with the outside world. All network traffic sent to and received by
the guest domains goes through and is forwarded by dom0. Routing uses the IP
addresses to figure out where to send the network packets.
Networking
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Routing acts at a higher level than the bridging technique, which only looked at the
MAC address to find out the destination. Routing and bridging accomplish the same Routing and bridging accomplish the same
task, but use different methods to move information from source to destination.
IP forwarding relays packets from one network segment to another if the proper
routing entries exist in the routing table. In this case we are using unicast, which
relays a packet from one link to another along a chain that connects the packet from
source to destination.
When we utilized the bridging configuration in the earlier section, we used
broadcasting, which duplicates a packet and sends a copy to each of the multiple
links, thus delivering a copy to every device on the network.
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