What does Routing Information Field (RIF) mean?
A routing information field (RIF) is an optional field located at the end of the media access control (MAC) address header and right before the user data. This field is used in token ring networks, and it contains routing information that is used by routing bridges to determine where to route tokens when forwarding data from one token ring network to another.
A source bridge cannot forward data without the information in the RIF. This is the common bridge used by token ring networks.