3Com S7906E Command Reference Manual page 1563

If LDP sessions have been established, you must use the reset mpls ldp command to reset LDP
sessions for this command to take effect.
Examples
# Set the label distribution control mode to independent for the public network LDP instance.
<Sysname> system-view
[Sysname] mpls ldp
[Sysname-mpls-ldp] label-distribution independent
# Set the label distribution control mode to independent for LDP instance vpn1.
<Sysname> system-view
[Sysname] mpls ldp vpn-instance vpn1
[Sysname-mpls-ldp-vpn-instance-vpn1] label-distribution independent
loop-detect
Syntax
loop-detect
undo loop-detect
View
MPLS LDP view, MPLS LDP VPN instance view
Default Level
1: Monitor level
Parameters
None
Description
Use the loop-detect command to enable loop detection.
Use the undo loop-detect command to disable loop detection.
By default, loop detection is disabled.
Note that you need to enable loop detection before enabling LDP on any interface.
Related commands: hops-count, path-vectors.
Examples
# Enable loop detection for the public network LDP instance.
<Sysname> system-view
[Sysname] mpls ldp
[Sysname-mpls-ldp] loop-detect
# Enable loop detection for LDP instance vpn1.
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