Enabling LDP Signaling and Services

When LDP is enabled, targeted sessions can be established to create remote adjacencies with nodes that are not directly connected. When service destination points (SDPs) are configured, extended discovery mechanisms enable LDP to send periodic targeted hello messages to the SDP’s far-end point. The exchange of LDP hellos triggers session establishment. The SDP’s signaling default enables tldp. The SDP uses the targeted-session parameters configured in the config>router>ldp> targeted-session context.

The service>sdp>ldp and router>lsp commands are mutually exclusive; you can either specify an LSP or enable an LDP. There cannot be two methods of transport in a single SDP.

To enable LDP on the SDP when an LSP is already specified, the LSP must be removed from the configuration using the no lsp lsp-name command. For further information about configuring SDPs, see the 7705 SAR Services Guide.

Use the following CLI syntax to enable LDP on an MPLS SDP:

CLI Syntax:

config>service>sdp#
    ldp
    signaling {off|tldp}

The following example displays an SDP configuration output with the signaling default tldp enabled.

ALU-1>config>service>sdp# info detail
----------------------------------------------
            description "MPLS: to-99"
            far-end 10.10.10.99
            ldp
            signaling tldp
            path-mtu 4462
            keep-alive
                hello-time 10
                hold-down-time 10
                max-drop-count 3
                timeout 5
                no message-length
                no shutdown
            exit
            no shutdown
----------------------------------------------
ALU-1>config>service>sdp#