Enabling compatibility with RFC 1583
RFC 1583 specifies a different method than RFC 2328 for selecting the optimal route to a destination in another AS. When multiple routes are available to the ASBR, OSPF selects the optimal route by using the following procedure:
Selects the route with the highest preference:
If RFC 2328 is compatible with RFC 1583, all these routes have equal preference.
If RFC 2328 is not compatible with RFC 1583, the intra-area route in a non-backbone area is preferred to reduce the burden of the backbone area. The inter-area route and intra-area route in the backbone area have equal preference.
Selects the route with lower cost if two routes have equal preference.
Selects the route with larger originating area ID if two routes have equal cost.
To avoid routing loops, set identical RFC 1583-compatibility on all routers in a routing domain as a best practice.
To enable compatibility with RFC 1583:
Step | Command | Remarks |
---|---|---|
1. Enter system view. | system-view | N/A |
2. Enter OSPF view. | ospf [ process-id | router-id router-id | vpn-instance vpn-instance-name ] * | N/A |
3. Enable compatibility with RFC 1583. | rfc1583 compatible | By default, this feature is enabled. |