Setting The Interval For Sending Advertisement Packets; Setting The Delaydown Timer - 3Com 4500G Family Configuration Manual

Enhanced mode: In this mode, DLDP actively detects neighbors when the corresponding neighbor
entries age out. The system can thus identify two types of unidirectional links: cross-connected
fibers and disconnected fibers.
Follow these steps to set DLDP mode:
To do...
Enter system view
Set DLDP mode

Setting the Interval for Sending Advertisement Packets

DLDP detects unidirectional links by sending Advertisement packets. To ensure that DLDP can detect
unidirectional links in time without affecting network performance, you need to set the advertisement
interval appropriately depending on your network environment. Typically, the interval should be set
shorter than one third of the STP convergence time. If the interval is set too long, STP loops may 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, you are recommended to use the default.
Follow these steps to set the interval for sending Advertisement packets:
To do...
Enter system view
Set the interval for
sending Advertisement
packets
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. 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
Use the command...
system-view
dldp work-mode { enhance |
normal }
Use the command...
system-view
dldp interval time
1-10
Remarks
—
Optional
Normal by default
Remarks
—
Optional
5 seconds by default