Route maps are similar to access lists in that they define match criteria and an action to take in the event of a match. Route maps are different from access lists in that they not only specify match criteria but also specify set criteria. The set action can modify a route, or route a packet according to the parameters of the packet.
2
Policy routes are static routes that use route maps to determine which packets should be routed and where the packets should be routed.
3
Route tags are fields within routing information packets that allow external information to be carried through the routing domain.
4
Route tags have no effect on the routing protocols that carry them.