3com 5500-ei pwr Guia De Referência

 

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When DLDP works in normal mode, the system can identify only the unidirectional link caused by 

fiber cross-connection. 

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When the DLDP protocol works in enhanced mode, the system can identify two types of 

unidirectional links: one is caused by fiber cross-connection and the other is caused by one fiber 

being not connected or being broken. To detect unidirectional links that are of the latter type, you 

need to configure the ports to operate at specific speed and in full duplex mode. Otherwise, DLDP 

cannot take effect. 

 

# Configure DLDP to work in enhanced mode. 

<Sysname> system-view 

System View: return to User View with Ctrl+Z. 

[Sysname] dldp work-mode enhance 

dldp delaydown-timer delaydown-time 

System view 

delaydown-time: Delaydown timer to be set (in seconds). This argument ranges from 1 to 5. 

Use the dldp delaydown-timer command to set the delaydown timer. 

Use the undo dldp delaydown-timer command to restore the default delaydown timer setting. 

By default, the DelayDown timer is set to 1 second. A period of 5 seconds is recommended. 

 

When a device in the active, advertisement, or probe DLDP state receives a port down message, it 

does not remove the corresponding neighbor immediately, nor does it transit to the inactive state. 

Instead, it transits to the delaydown state and starts the DelayDown timer. In delaydown state, the 

device retains the related DLDP neighbor information. When the DelayDown timer expires, the DLDP 

neighbor information is removed.