Routing Protocols Summary - dummies

By Edward Tetz

The following table is a summary of the essential characteristics of the major routing protocols and can be used as part of your evaluation criteria. It has the most common protocols and a number of points of evaluation.

Routing Protocol Evaluation Criteria
Type Distance-vector Distance-vector Link-state Distance-vector
Convergence Time Slow Slow Fast Fast
VLSM No Yes Yes Yes
Bandwidth Consumption High High Low Low
Resource Consumption Low Low High Low
Multi-path Support No Yes Yes Yes
Scales Well No No Yes Yes
Proprietary No No No Yes
  • Convergence Time: Convergence time is the point at which all routers on your network know about all current routes for the network. When a router is added or removed from a network, a certain amount of time — convergence time — must pass before this change is propagated to all routers on the network.

  • Variable length subnet masks (VLSM): This term refers to whether all routers on the network are required to use the same subnet mask. This requirement reduces your flexibility in assigning IP address network IDs to the network segments on your network.

  • Bandwidth Consumption: This term refers to the amount of necessary network bandwidth to maintain and distribute routing table information on the network. To share and distribute routing table information, all routing protocols need to send an amount of data over the network, and some send more than others.

  • Resource Consumption: In calculating and maintain routing table information on a router, a certain amount of processing power and memory is used.

  • Multi-path Support: When routes are discovered on the network that have loops in their paths, some segments have two possible routes, which represent multiple paths. Some routing protocols have support for multiple paths, by storing alternative paths in their routing information.

  • Scales Well: Some routing protocols operate well on small networks, but as the number of routers increases on the network, the routing protocol does not function as well. Routing protocols that can be used on small to very large networks scale well in size.

  • Proprietary: The routing protocol based on open standards or a proprietary protocol owned by one company can affect the level of support and the speed of changes.