Each domain network interface is connected to a virtual network
interface in dom0 by a point to point link (effectively a ``virtual
crossover cable''). These devices are named vif<domid>.<vifid> (e.g. vif1.0 for the first
interface in domain 1, vif3.1 for the second interface in
domain 3).
Traffic on these virtual interfaces is handled in domain 0 using
standard Linux mechanisms for bridging, routing, rate limiting, etc.
Xend calls on two shell scripts to perform initial configuration of
the network and configuration of new virtual interfaces. By default,
these scripts configure a single bridge for all the virtual
interfaces. Arbitrary routing / bridging configurations can be
configured by customizing the scripts, as described in the following
section.
