Configuration Reference - interface

gateway (text)
Gateway of the named interface.

ip (text)
IP adress of the named interface - note that this should mirror the OS-level configuration but it does not make any OS-level changes.

mask (text)
Network mask of the named interface.

type (multi)
Options: internal;managed;monitor
Describes "type" of named interface. Internal describes internal client networks, managed (aka external) interfaces have the administrative GUI running on them, and monitor is the interface that snort listens on.