H3C S5120-EI Series - Setting the Delaydown Timer; Setting the Port Shutdown Mode

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To set the interval to send Advertisement packets:
Ste
p
Command Remarks
1. Enter system view.
system-view N/A
2. Set the interval to send
Advertisement packets.
dldp interval time
Optional.
5 seconds by default.
NOTE:
• The interval for sending Advertisement packets applies to all DLDP-enabled ports.
• To enable DLDP to operate properly, make sure the intervals for sending Advertisement packets on both
sides of a link are the same.
Setting the delaydown timer
On some ports, when the Tx line fails, the port goes down and then comes up again, causing optical
signal jitters on the Rx line. When a port goes down due to a Tx failure, the device transits to the
DelayDown state instead of the Inactive state to prevent the corresponding neighbor entries from being
removed. At the same time, the device triggers the DelayDown timer. If the port goes up before the timer
expires, the device restores the original state; if the port remains down when the timer expires, the device
transits to the Inactive state.
To set the DelayDown timer:
Ste
p
Command Remarks
1. Enter system view.
system-view N/A
2. Set the DelayDown
timer.
dldp delaydown-timer time
Optional.
1 second by default.
NOTE:
DelayDown timer setting applies to all DLDP-enabled ports.
Setting the port shutdown mode
On detecting a unidirectional link, the ports can be shut down in one of the following two modes:
• Manual mode—This mode applies to low performance networks, where normal links may be
treated as unidirectional links. It protects data traffic transmission against false unidirectional links.
In this mode, DLDP only detects unidirectional links but does not automatically shut down
unidirectional link ports. Instead, the DLDP state machine generates log and traps to prompt you to
manually shut down unidirectional link ports with the shutdown command. H3C recommends that
you do as prompted. Then the DLDP state machine transits to the Disable state.
• Auto mode—In this mode, when a unidirectional link is detected, DLDP transits to Disable state,
generates log and traps, and sets the port state to DLDP Down.
On a port with both remote OAM loopback and DLDP enabled, if the port shutdown mode is auto mode,
the port will be shut down by DLDP when it receives a packet sent by itself, causing remote OAM
loopback to operate improperly. To prevent this, set the port shutdown mode to manual mode.