Essentially, routing
buffers and forwards network data packets to their destination addresses. When we
use routed networking, dom0 acts as a router to the outside world and a junction
between the outside world and the guest domains, and buffers and transfers data
packets among the domains. dom0 is the only domain that is actually connected to
the physical Ethernet interface, and all the traffic from the various domains to the
outside world go through it. It creates, maintains and uses a routing table in order to
send the network packets to the right destinations.
The routed network configuration work on network packets while the bridged
network configuration works on Ethernet frames. So, while a network bridge
will direct the Ethernet frames by utilizing hardware MAC addresses, a network
router will make routing decisions based on assigned IP Addresses. This enables
network packets to be forwarded by the router from one host to another based on
the addressing scheme, without the need to know or maintain the entire path from
source to destination.
In this section we will look at what happens behind the scenes and how Xen actually
sets up your network configuration to use routing.
Time for Action??”Using Routed Networking
We are going to configure the domU to use routed networking, and then create a
guest domain that uses routed networking.
1. We need to stop xend first as we will be modifying its configuration file:
# service xend stop
2.
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