The RoutingInformation Field(RIF) is a data field in the 802.5 header that contains information for source routing bridges and about the route a data packet should take through the LAN segments of a Token Ring. The RIF data field contains ring and bridge numbers.
The Routing Information Field consists of the 16-bit Routing Control( RC) field, which contains the control information for the route, and one or more Route Designators( RD) that describe the route. The 16 bits long RC field contains the 3 bits long route type( RT), a 5 bits long length field in which the total RIF length is contained, a direction bit, a three bits long information about the longest frame and four reserved bits.
The RD (Route Destination Field) part of the RIF field consists of one or more RD fields containing the exact route with segment and bridge numbers.