During the installation of your XenServer, you only configure basic settings for your management Network Interface Card (NIC). Further, and maybe even more complex, configuration of your NICs can be set with the XenCenter GUI or with the xe CommandLine Interface (CLI).
The xe CLI can be run locally at the command prompt of the XenServer Console within XenCenter or you can use the ex.exe, which is part of the XenCenter installation and allows and administrator to remotely manage a XenServer from the command prompt of the Windows desktop. With the CLI you can also easily script some of the common tasks to perform on a XenServer.
This post contains additional xe CLI examples that are used for NIC settings on your XenServer.