Use of policy-based routing with static or dynamic routing

If a policy-based route table is configured with both static routes and dynamic routing parameters, review the considerations in Use of static routing with OMPROUTE and in Use of IPv6 static routing with router advertisements. The same considerations apply with one exception; references that are made to static routes in those topics refer to static routes that are configured by using the Route parameter on the RouteTable policy statement.

When policy-based routing is used, policies are defined that instruct the TCP/IP stack to use specific policy-based route tables when it is making routing decisions, which are based on the traffic that is being routed. The main route table is used only when one of the following conditions are true:

• The traffic for which a route is being selected does not match any active policy-based routing rule.
• The traffic for which a route is being selected matches an active policy-based routing rule. However, no usable route exists in the policy-based route tables that are specified by policy to be used for the traffic, and the policy indicates that the main route table is to be used when this situation occurs.