H3C Technologies H3C S12500 Series Switches - Manual (Page 55)

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Setting DLDP mode
DLDP operates in normal or enhanced mode. In normal mode, DLDP does not actively detect neighbors
when the corresponding neighbor entries age out. In enhanced mode, DLDP actively detects neighbors
when the corresponding neighbor entries age out.
To set DLDP mode:
Step Command Remarks
1. Enter system view. system-view N/A
2. Set DLDP mode. dldp work-mode { enhance | normal }
Optional.
Normal by default.
Setting the interval to send advertisement packets
DLDP detects unidirectional links by sending Advertisement packets. To make sure that DLDP can detect
unidirectional links in time without affecting network performance, set the advertisement interval
appropriately depending on your network environment. The interval should be set shorter than one third
of the STP convergence time. If the interval is set too long, STP loops might occur before unidirectional
links are detected and shut down. If the interval is set too short, the number of advertisement packets will
increase. In most cases, H3C recommends that you use the default interval.
To set the interval to send Advertisement packets:
Step 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 correctly, 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 switch transitions to the
DelayDown state instead of the Inactive state to prevent the corresponding neighbor entries from being
removed. At the same time, the switch triggers the DelayDown timer. If the port goes up before the timer
expires, the switch restores the original state; if the port remains down when the timer expires, the switch
transits to the Inactive state.
To set the DelayDown timer: