23
337B
Notification delay for LDP restart or active/standby switchover
When an LDP restart or an active/standby switchover occurs, LDP takes time to converge, and LDP
notifies IGP of the LDP-IGP synchronization status as follows:
•
If a notification delay is not configured, LDP immediately notifies IGP of the current
synchronization states during convergence, and then updates the states after LDP
convergence. This could impact IGP processing.
•
If a notification delay is configured, LDP notifies IGP of the LDP-IGP synchronization states in
bulk when one of the following events occurs:
{
LDP recovers to the state before the restart or switchover.
{
The maximum delay timer expires.
152B
LDP over MPLS TE
As shown in
674H
Figure 14
, in a layered network, MPLS TE is deployed in the core layer, and the
distribution layer uses LDP as the label distribution protocol. To set up an LDP LSP across the core
layer, you can establish the LDP LSP over the existing MPLS TE tunnel to simplify configuration. You
only need to enable LDP on the tunnel interfaces of the ingress and egress nodes for the MPLS TE
tunnel. An LDP session will be established between the tunnel ingress and egress. Label Mapping
messages are advertised through the session and an LDP LSP is established. The LDP LSP is
carried on the MPLS TE LSP, creating a hierarchical LSP. For more information about MPLS TE
tunnels, see "
675H
Configuring MPLS TE
."
Figure 14 LDP over MPLS TE
153B
Protocols
•
RFC 5036,
LDP Specification
•
draft-ietf-mpls-ldp-ipv6-09.txt
32B
LDP configuration task list
Tasks at a glance
Enable LDP:
5.
(Required.)
676H
Enabling LDP globally
6.
(Required.)
677H
Enabling LDP on an interface