Setting The Delaydown Timer; Setting The Port Shutdown Mode - 3Com 4510G Configuration Manual

To do...
Set the interval for
sending Advertisement
packets
The interval for sending Advertisement packets applies to all DLDP-enabled ports.
Set the interval for sending Advertisement packets to a value no 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, and it takes a long time for the device to detect unidirectional links, thus causing more
traffic forwarding errors; if the interval is too short, unnecessary Advertisement packets can be
generated to consume bandwidth. Therefore, you are recommended to use the default value.
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...
Enter system view
Set the DelayDown timer
DelayDown timer setting applies to all 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.
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
Use the command...
dldp interval time
Use the command...
system-view
dldp delaydown-timer time
4-10
Remarks
Optional
5 seconds by default
Remarks
—
Optional
1 second by default