Allied Telesis AT-8550 - Manual (Page 252)

Debug Tracing
B-8
Debug Tracing
The switch software includes a debug-tracing facility for the switch.
The show debug-tracing command can be applied to one or all
VLANs, as follows:
show debug-tracing {vlan <name>}
The debug commands should only be used under the guidance of
Allied Telesyn technical personnel.