Alcatel-Lucent 7210 SAS M User Manual page 289

LDP Configuration Commands
prefer-tunnel-in-tunnel
Syntax [no] prefer-tunnel-in-tunnel
Context config>router>ldp
Description This command specifies to use tunnel-in-tunnel over a simple LDP tunnel. Specifically, the user
packets for LDP FECs learned over this targeted LDP session can be sent inside an RSVP LSP which
terminates on the same egress router as the destination of the targeted LDP session. The user can
specify an explicit list of RSVP LSP tunnels under the Targeted LDP session or LDP will perform a
lookup in the Tunnel Table Manager (TTM) for the best RSVP LSP. In the former case, only the
specified LSPs will be considered to tunnel LDP user packets. In the latter case, all LSPs available to
the TTM and which terminate on the same egress router as this target ed LDP session will be
considered. In both cases, the metric specified under the LSP configuration is used to control this
selection.
Note that the lookup in the TTM will prefer a LDP tunnel over an LDP-over-RSVP tunnel if both are
available. Also note that the tunneling operates on the dataplane only. Control packets of this targeted
LDP session are sent over the IGP path.
7210 SAS M, T, X, R6, Mxp MPLS Configuration Guide Page 289