Allied Telesis AT-S63 - Manual (Page 178)

Chapter 8: Port Parameter Commands
178 Section I: Basic Operations
unknown - The port status is unknown.
 ifLinkUpDownTrapEnable - Whether or not link traps have been
enabled for the port, one of the following:
Enabled - Link traps are enabled. To disable link traps, see “DISABLE
INTERFACE LINKTRAP” on page 153.
Disabled - Link traps are disabled. To enable link traps, see “ENABLE
INTERFACE LINKTRAP” on page 157.
Example
The following command displays information about port 21:
show interface=21