(Optional) Configuring the Outbound LDP Policy

An outbound LDP policy can be configured to prevent the establishment of unwanted LSPs, efficiently using memory.

Context

An LSR is usually able to send Label Mapping messages to both upstream and downstream LDP peers, speeding up LDP LSP convergence. This leads to a great number of unwanted LSPs to be established, wasting resources. An outbound LDP policy can be configured to reduce the number of Label Mapping messages to be sent. The outbound LDP policies help reduce the number of unwanted LSPs to be established and efficiently use memory.

The outbound LDP policy helps an LSR provide a specific function based on one of the following parameters:

none: filters out all forwarding equivalence classes (FECs). A local node does not send IGP route-based Label Mapping messages to a specified peer.
host: allows FECs for host routes to pass. A local node sends host route-based Label Mapping messages to a specified peer.
ip-prefix: allows only the FEC for a specified IP prefix to pass. A local node sends IP prefix-based Label Mapping messages to a specified peer.

Procedure

Run system-view
The system view is displayed.
Run mpls ldp
The MPLS-LDP view is displayed.
(Optional) Run ipv4-family
The MPLS LDP IPv4 view is displayed.
Perform either of the following steps to apply the outbound policy that allows Label Mapping messages for specified routes to be sent to a specified LDP peer:
- To configure an outbound policy that allows Label Mapping messages for specified IGP routes to be sent to a specified LDP peer, run outbound peer { peer-id | peer-group peer-group-name | all } fec { none | host | ip-prefix prefix-name }
- To configure an outbound policy that allows Label Mapping messages for specified labeled BGP routes to be sent to a specified LDP peer, run outbound peer { peer-id | peer-group peer-group-name | all } bgp-label-route { none | ip-prefix prefix-name }
To apply a policy associated with a single FEC range to an LDP peer group or all LDP peers to which the local LSR sends Label Mapping messages, configure either the peer-group peer-group-name or all parameter in the command.
If multiple outbound policies are configured for a specified LDP peer, the first configured one takes effect. For example, the following two outbound policies are configured:
```
outbound peer 2.2.2.2 fec host
outbound peer peer-group group1 fec none
```
As group1 also contains an LDP peer with peer-id of 2.2.2.2, the following outbound policy takes effect:
```
outbound peer 2.2.2.2 fec host
```
If two outbound policies are configured in sequence and the peer parameters in the two commands are the same, the second command overwrites the first one. For example, the following two outbound policies are configured:
```
outbound peer 2.2.2.2 fec host
outbound peer 2.2.2.2 fec none
```
The second configuration overwrites the first one. This means that the following outbound policy takes effect on the LDP peer with peer-id of 2.2.2.2:
```
outbound peer 2.2.2.2 fec none
```
MPLS and MPLS LDP must be enabled globally before an outbound policy is configured.

To delete all outbound policies simultaneously, run the undo outbound peer all command.
Run commit
The configuration is committed.