Network Routing

Network interfaces

Because machines in a data center usually have multiple network interfaces, questions will sometimes arise about which interfaces particular kinds of traffic should traverse. For example, it’s relatively common to see a machine with a front-end network interface connected to one VLAN for communication to the web servers and a back-end network interface connected to a different VLAN for communication to the database servers. In this case, the server must be told which interface to use in order to reach a particular destination IP address.