At this point, we have one system that is able to send out data onto the external network. The remaining machines only have routes to the internal network defined on them, which means that while they can talk to each other quite happily, they don't know how to send out data onto the Internet. To allow them to do this, we'll create a default route on each system as before, but this time it will point to xenon. We will also need to update their nsswitch.conf as we did previously to use DNS for hosts lookup. Once this is complete, if any systems need to send or receive data from a machine they don't know about, they will pass it to xenon, which in turn will send it externally (see Figure 13.2).