R21xx-HP FlexFabric 11900 MPLS Command Reference

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<Sysname> reset mpls ldp
# Reset all LDP sessions in the VPN instance vpn1.
<Sysname> reset mpls ldp vpn-instance vpn1
session protection
Use session protection to enable session protection.
Use undo session protection to disable session protection.
Syntax
session protection [ duration time ] [ peer peer-prefix-list-name ]
undo session protection
Default
Session protection is disabled.
Views
LDP view
Predefined user roles
network-admin
Parameters
duration time: Specifies the session protection duration time in the range of 30 to 2147483 seconds. If
you do not specify the duration, session protection always takes effect.
peer peer-prefix-list-name: Specifies an IP prefix list by its name, a case-sensitive string of 1 to 63
characters. Sessions to the peers whose LSR IDs are permitted by the specified IP prefix list are protected.
If you do not specify this option, all sessions established by the Basic Discovery mechanism are
protected.
Usage guidelines
If two LDP peers have both a direct link and an indirect link in between, you can configure this feature to
protect their LDP session when the direct link fails.
LDP establishes both a Link Hello adjacency over the direct link and a Targeted Hello adjacency over the
indirect link with the peer. When the direct link fails, LDP deletes the Link Hello adjacency but still
maintains the Targeted Hello adjacency. In this way, the LDP session between the two peers is kept
available, and the FEC-label mappings based on this session are not deleted. When the direct link
recovers, the LDP peers do not need to re-establish the LDP session or re-learn the FEC-label mappings.
When you enable the session protection function, you can specify the session protection duration. If the
Link Hello adjacency does not recover within the duration, LDP deletes the Targeted Hello adjacency and
the LDP session. If you do not specify the session protection duration, the two peers always maintain the
LDP session over the Targeted Hello adjacency.
Examples
# Enable protection for the session to the peer 3.3.3.3, and set the session protection duration to 120
seconds.
<Sysname> system-view
[Sysname] ip prefix-list protected-peer-list index 1 permit 3.3.3.3 32
[Sysname] mpls ldp
[Sysname-ldp] session protection duration 120 peer protected-peer-list