Configuring Link Protection for OSPF

You can configure link protection for any interface for which OSPF is enabled. When you enable link protection, the Junos OS creates an alternate path to the primary next hop for all destination routes that traverse a protected interface. Use link protection when you assume that only a single link might become unavailable but that the neighboring node would still be available through another interface.

Link protection is supported on the following:

• OSPFv2 and OSPFv3 interfaces
• OSPFv3 unicast realms
• OSPFv2 unicast topologies, except for multicast topologies
• All routing instances supported by OSPFv2 and OSPFv3
• Logical systems

To configure link protection for an OSPF interface:

• Include the link-protection statement at the [edit protocols (ospf | ospf3) area area-id interface interface-name hierarchy level.

Best Practice: When you configure link protection for OSPF, you must also configure a per-packet load-balancing routing policy to ensure that the routing protocol process installs all the next hops for a given route in the routing table.

In the following example, the OSPF interface so-0/0/0.0 in area 0.0.0.0 is configured for link protection. If a link for a destination route that traverses this interface becomes unavailable, the Junos OS creates a loop-free backup path through another interface on the neighboring node, thus avoiding the link that is no longer available.

Related Topics

• Loop-Free Alternate Routes for OSPF Overview
• link-protection