1.4 Routing Protocol
1.4.3 Classes of routing protocols
Most routing protocols are based on one of two routing algorithms: distance vector or link state.

The distance vector routing approach determines the direction (vector) and distance to any link in the internetwork.

The link-state (also called shortest path first) approach re-creates the exact topology of the entire internetwork (or at least the portion in which the router is situated).

The balanced hybrid approach combines aspects of the link-state and distance vector algorithms.

The next several pages cover procedures and problems for each of these routing algorithms and present techniques for minimizing the problems.