H3C Technologies H3C WX6000 Series Access Controllers - Manual (Page 302)

27-10
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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.
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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
To do… Use the command… Remarks
Enter system view system-view —
Set the DelayDown timer dldp delaydown-timer time
Optional
1 second by default
DelayDown timer setting applies to
all the 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.
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Manual mode. This mode applies to networks with low performance, where normal links may be
treated as unidirectional links. It protects service packet transmission against false unidirectional
links. In this mode, DLDP only detects unidirectional links and generates log and traps. The
operations to shut down unidirectional link ports are accomplished by the administrator.
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Auto mode. In this mode, when a unidirectional link is detected, DLDP transits to Disable state,
generates log and traps, and set the port as DLDP Down.
Follow these steps to set port shutdown mode
To do… Use the command… Remarks
Enter system view system-view —
Set port shutdown mode
dldp unidirectional-shutdown { auto |
manual }
Optional
auto by default