Allied Telesis AT-S26 - Manual (Page 81)

AT-S26 Version 2.0.1 User’s Guide
81
MAC Address Table
The MAC address table (also referred to as the forwarding table) is a
snapshot of the source MAC addresses that a switch has learned and
stored in its volatile memory. When a frame is received by a port on a
switch, the source address of the frame is inspected to determine
whether or not the address is already in the table. If it is not, the switch
adds the address to the table.
Each AT-9006 Series switch maintains its own MAC address table. Each
table can hold up to 8,000 addresses. To prevent the table from
becoming filled with addresses of devices that have become inactive
and are no longer sending frames, MAC address are periodically deleted
from the table. An address is deleted if a MAC address in the table does
not reappear on any port after a specified period of time has elapsed.
The default time period is 300 seconds (5 minutes). This aging time is
configurable, as explained in the procedure Changing the Aging Time
of the MAC Address Table on page 85.
If you reset the switch or remove power, the table is cleared but
immediately gets updated as soon as the switch is operational and the
ports start to detect MAC addresses in incoming packets.
Each switch also maintains a static MAC address table. This table
contains MAC addresses that are entered manually and are not aged out
after a period of time. The only way that a static address is removed is if it
is manually deleted from the table. When you enter a static address, you
specify the port when the node with the address is connected. Each
switch is responsible for maintaining its own static MAC address table.
Note
The MAC address for an AT-9006 Series switch is provided on the
MAC address label directly above the RS232 management port on
the switch front panel. You can also determine the MAC address by
running the switch diagnostics program, as explained in Chapter 2,
Managing a Switch.