Overview of Routing Policies
Definition
Routing policies are used to filter routes and set route attributes. By changing the attributes of a route, a route policy can change the path that network traffic passes through.
Purpose
When advertising, receiving, and importing routes, routing protocols implement certain policies to filter routes and change the attributes of the routes based on the following networking requirements:
Control route receiving and advertising.
Only required and valid routes are received or advertised. This reduces the size of the routing table and improves network security.
Control route importing.
A routing protocol may import routes discovered by other routing protocols. Only routes that satisfy certain conditions are imported to meet the requirements of the protocol.
Modify attributes of specified routes.
Attributes of routes that are filtered by a routing policy are modified to meet the requirements of the local device.
Benefits
- System resources are saved by controlling the size of the routing table.
- Network security is improved by controlling the route receiving, advertising and importing.
- Network performance is improved by modifying the attributes of routes for proper traffic planning.