Advertising Explicit Null Labels to BGP Peers
You can advertise an explicit null label (label 0) out of the egress router for a label-switched path (LSP). By default, the routing device advertises label 3. Enabling explicit null allows the routing device to send out label 0. Advertising explicit null labels is used for peers in the same BGP group.
Configure the labeled-unicast statement with the explicit-null option. As with regular BGP configuration, the family statement can be specified.
To advertise an explicit null label, include the following statements in the configuration:
For a list of hierarchy levels at which you can include this statement, see the statement summary section for this statement.
Specify the connected-only statement to advertise explicit null labels between connected routes only (direct routes and loopback routes).
 | Note: The connected-only statement is required to advertise explicit null labels. |
| Note: Explicit null labels are supported for the IPv4 (inet) family only. |
