Routing: Route Summarization

Route - Summarization

Summarization is the process in which the administrator collapses many routes with a long mask to form another route with a shorter mask. Route summarization reduces the size of routing tables and makes routing function more efficiently. Route summarization also helps make networks more stable by reducing the number of updates that are sent when subnets change state. Route summarization makes classless inter-domain routing (CIDR) possible. Variable-length subnet masking (VLSM) promotes the use of route summarization. Some dynamic routing protocols engage in route summarization automatically for changes in a major classful network, whereas others do not.