Understanding Routing Policy Tests
Routing policy tests provide a method for verifying the effectiveness of your policies before applying them on the routing device. Before applying a routing policy, you can issue the test policy command to ensure that the policy produces the results that you expect:
Keep in mind that different protocols have different default policies that get applied if the prefix does not match the configured policy. For BGP this is accept, but for RIP it is reject. The test policy command always uses accept as the default policy, so unless you explicitly reject all routes that you do not want to match you might see more routes matching than you want.
The default policy of the test policy command accepts all routes from all protocols. Test output can be misleading when you are evaluating protocol-specific conditions. For example, if you define a policy for BGP that accepts routes of a specified prefix and apply it to BGP as an export policy, BGP routes that match the prefix are advertised to BGP peers. However, if you test the same policy using the test policy command, the test output might indicate that non-BGP routes have been accepted.
Example: Testing a Routing Policy
Test the following policy, which looks for unwanted routes and rejects them:
Test this policy against all routes in the routing table:
Test this policy against a specific set of routes: