RIF contains a 2-byte RIF header and one or more route descriptors. Each route descriptor contains a 12-bit ring number and a 4-bit bridge number. The values for the Type field contained in the header indicate the following:
00Nonbroadcast (specific route): Indicates that this is a regular frame that should be routed to the destination following the information in the route descriptors.
10All-routes broadcast: Indicates that this is an all-rings explorer packet that should take all possible routes to the destination.
11Single-route: Indicates that this is a limited broadcast that should take one path to the destination.