DLDP Configuration Task List 191
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DLDP takes effect only when it is enabled both globally and on a port.
Setting DLDP Mode Follow these steps to set DLDP mode:
Setting the Interval for
Sending Advertisement
Packets
You can set the interval for sending Advertisement packets to enable 
unidirectional links to be detected in time.
Follow these steps to set the interval for sending Advertisement packets:
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CAUTION:
■ Set the interval for sending Advertisement packets to a value not longer than 
one-third of the STP convergence time. If the interval is too long, STP loops 
may occur before unidirectional links are torn down; if the interval is too short, 
network traffic may increase in vain due to excessive Advertisement packets.
■ 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. In 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 devices transits to the Inactive state.
Follow these steps to set the DelayDown timer
Enable DLDP dldp enable Required
Disabled on a port by default
You can perform this operation on an 
optical port or an electrical port.
To do… Use the command…  Remarks 
To do…  Use the command…  Remarks 
Enter system view  system-view - 
Set DLDP mode  dldp work-mode { enhance | 
normal } 
Optional
Normal by default
To do…  Use the command…  Remarks 
Enter system view  system-view - 
Set the interval for 
sending Advertisement 
packets 
dldp interval time Optional
5 seconds by default
The interval for sending Advertisement 
packets applies to all the DLDP-enabled 
ports.