Technical Documentation

Instance Export Using an IGP Export Policy

Current configurations that use routing table groups define a policy with a from instance statement to select routes in an IGP export policy. However, no policy controls the export process itself. Therefore, the configuration has been simplified so that you do not need to specify additional policies to control the export process. Many current interinstance implementations use an IGP export policy model. The policy model has been extended to support both interinstance route export and IGP export.

If the [edit routing-options auto-export] hierarchy is enabled when an instance-import policy has not been defined, OSPF and IS-IS export policies are automatically examined for the presence of from instance statements. If these statements are present, the instance-import policy is selected.

This verification process prevents attribute changes from being applied twice. It also prevents the second policy (IGP export policy) from causing conflicting routing choices. The following is an example of a configuration using an IGP export policy:

[edit]policy-options {policy-statement {red-ospf-export {from instance blue;then {tag 1;accept;}}}}routing-instances {red {routing-options {auto-export;}protocols ospf {export red-ospf-export;}}blue {}}

Published: 2010-04-15