Configuring automatic route advertisement to direct traffic to an MPLS TE tunnel
You can use either IGP shortcut or forwarding adjacency to implement automatic route advertisement. When you use IGP shortcut, you can specify a metric for the TE tunnel. If you assign an absolute metric, the metric is directly used as the MPLS TE tunnel's metric. If you assign a relative metric, the MPLS TE tunnel's metric is the assigned metric plus the IGP link metric.
Before configuring automatic route advertisement, perform the following tasks:
Enable OSPF or IS-IS on the tunnel interface to advertise the interface address to OSPF or IS-IS.
Enable MPLS TE for an OSPF area or an IS-IS process by executing the mpls te enable command in OSPF area view or IS-IS view.
Follow these restrictions and guidelines when you configure automatic route advertisement:
The destination address of the MPLS TE tunnel can be the LSR ID of the egress node or the primary IP address of an interface on the egress node. As a best practice, configure the destination address of the MPLS TE tunnel as the LSR ID of the egress node.
If you configure the tunnel destination address as the primary IP address of an interface on the egress node, you must enable MPLS TE, and configure OSPF or IS-IS on that interface. This makes sure the primary IP address of the interface can be advertised to its peer.
The route to the tunnel interface address and the route to the tunnel destination must be in the same OSPF area or at the same IS-IS level.
Configuring IGP shortcut
Step | Command | Remarks |
|---|---|---|
1. Enter system view. | system-view | N/A |
2. Enter interface view. | interface tunnel tunnel-number [ mode mpls-te ] | N/A |
3. Enable IGP shortcut. | mpls te igp shortcut [ isis | ospf ] | By default, IGP shortcut is disabled. If no IGP is specified, both OSPF and IS-IS will include the MPLS TE tunnel in route calculation. |
4. Assign a metric to the MPLS TE tunnel. | mpls te igp metric { absolute value | relative value } | By default, the metric of an MPLS TE tunnel equals its IGP metric. |
Configuring forwarding adjacency
To use forwarding adjacency, you must establish two MPLS TE tunnels in opposite directions between two nodes, and configure forwarding adjacency on both the nodes.
To configure forwarding adjacency:
Step | Command | Remarks |
|---|---|---|
1. Enter system view. | system-view | N/A |
2. Enter MPLS TE tunnel interface view. | interface tunnel tunnel-number [ mode mpls-te ] | N/A |
3. Enable forwarding adjacency. | mpls te igp advertise [ hold-time value ] | By default, forwarding adjacency is disabled. |