Allied Telesis AT-S63 - Manual (Page 77)

AT-S63 Management Software Features Guide
Section I: Basic Operations 77
MAC address table from becoming filled with addresses of nodes that are
no longer active.
The period of time that the switch waits before purging an inactive dynamic
MAC address is called the aging time. This value is adjustable on the
AT-9400 Switch. The default value is 300 seconds (5 minutes).
The MAC address table can also store static MAC addresses. A static
MAC address is a MAC address of an end node that you assign to a switch
port manually. A static MAC address remains in the table indefinitely and
is never deleted, even when the end node is inactive.
You might need to enter static MAC addresses of end nodes the switch
does not learn in its normal dynamic learning process, or if you want a
MAC address to remain permanently in the table, even when the end node
is inactive.