Parallel Tunnel Support for Fabric Extend

You can create parallel Fabric Extend IP tunnels between the same two nodes to create a backup Fabric Extend adjacency. Parallel tunnels are active simultaneously.

The switch supports the following parallel tunnel configuration:

• The primary tunnel configuration uses the global IP tunnel source address that you configure for IS-IS by using the ip-tunnel-source-address CLI command.

• The backup tunnel configuration uses an additional source address and optional VRF that you configure for the IS-IS logical interface by using logical-intf isis CLI command parameters.

Note

The backup tunnel can be either a native Fabric Extend tunnel or an IPsec-encrypted Fabric Extend tunnel for products that support Fabric IPsec Gateway.

IS-IS adjacencies operate the same through parallel tunnels as existing parallel IS-IS adjacency support:

• If multiple adjacencies exist between the same two nodes, only one adjacency is active and the rest are backup.

• The adjacency with the lowest metric is the active adjacency.

• If multiple interfaces use the same metric, the one with the lowest logical interface ID from the node with the lowest system ID is the active adjacency.

Note

These are the restrictions to configure Fabric Extend:

• Only two different Fabric Extend tunnel IP sources are supported.
• The same IP source on different VRFs is not supported.
• The same IP destination on different VRFs is not supported.

For configuration steps, see the following tasks:

• CLI configuration steps: Configure Fabric Extend

• EDM configuration steps: Configure Fabric Extend Logical Interfaces