Dell PowerConnect 3024 User Manual page 37

Dynamic Addresses
The Dynamic Addresses lookup table allows you to view the MAC addresses that are currently in the address database. When addresses are in the database,
the packets intended for those addresses are forwarded directly to those ports. You can filter out the table by port, VLAN, and MAC address by checking those
fields.
Dynamic MAC address learning is enabled by default. This is the standard mode for a network switch. In some networks, you may want to create a secured
network by disabling the dynamic address learning capabilities. When this is done, all current dynamic address entries will be locked in. These addresses will
not age out and new addresses will not be learned.
In addition, if a new address is detected on a port, the switch will disable the port with the new address, save the current settings to NVRAM, and send out a
Simple Network Management Protocol (SNMP) trap warning. This is useful for locking out systems that attempt to access the network that were not on the
network previous to the lockdown. Once a port is automatically disabled, you can reenable the port manually. The NVRAM will only be saved the first time a
given port detects a new address. If the aging time is raised prior to disabling the dynamic address learning, it will allow enough time for all current MAC
address to be learned by the switch without the possibility of aging out.
NOTE: The console interface can display up to 28 address entries. To see more than 28 entries, use the web interface.
Address Aging
In the Address Aging screen, you can specify how long an address stays available to the switch if it is not configured as static.
The following field is available:
Aging Time — sets the time before an address is purged from system. You can change this value to any number between 10 and 1,000,000 seconds.
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