Supported Platforms
Related Documentation
- ACX, M, MX, PTX, T Series, QFabric System, QFX Series standalone switches
- Example: Disabling OSPFv2 Compatibility with RFC 1583
OSPFv2 Compatibility with RFC 1583 Overview
In the first implementation of OSPF (RFC1583, OSPF Version 2), the summary route assumes the cost of the granular route with the lowest cost. OSPF RFC 2328, OSPF Version 2 changes the behavior so that the summary route assumes the cost of the granular route with the highest cost. OSPF readvertises the summary route whenever the cost of the summary changes. When using the default RFC 1583 behavior, this happens when the granular route with the lowest metric is changed or lost. When RFC 2328 is used, this happens when the granular route with the highest cost is changed or lost.
By default, the Junos OS implementation of OSPF is compatible with RFC 1583. This means that Junos OS maintains a single best route to an autonomous system (AS) boundary router in the OSPF routing table, rather than multiple intra-AS paths, if they are available. You can disable compatibility with RFC 1583. It is preferable to do so when the same external destination is advertised by AS boundary routers that belong to different OSPF areas. When you disable compatibility with RFC 1583, the OSPF routing table maintains the multiple intra-AS paths that are available, which the router uses to calculate AS external routes as defined in RFC 2328. Being able to use multiple available paths to calculate an AS external route can prevent routing loops.
Related Documentation
- ACX, M, MX, PTX, T Series, QFabric System, QFX Series standalone switches
- Example: Disabling OSPFv2 Compatibility with RFC 1583
Published: 2014-07-23
Supported Platforms
Related Documentation
- ACX, M, MX, PTX, T Series, QFabric System, QFX Series standalone switches
- Example: Disabling OSPFv2 Compatibility with RFC 1583
