MAC Address Tables
Types of MAC Addresses
Cisco 220 Series Smart Switches Administration Guide Release 1.1.0.x
This chapter describes how to add MAC addresses to the switch and includes the
following topics:
•
Types of MAC Addresses
•
Configuring Static MAC Addresses
•
Configuring Static MAC Address Filter
•
Configuring Dynamic MAC Address Aging Time
•
Querying Dynamic MAC Addresses
•
Configuring Reserved MAC Addresses
There are two types of MAC addresses: static and dynamic. Depending on their
type, MAC addresses are either stored in the Static Address table or in the
Dynamic Address table, along with VLAN and port information.
Static addresses are configured by the user, and therefore, they do not expire. A
new source MAC address that appears in a frame arriving at the switch is added
to the Dynamic Address table. This MAC address is retained for a configurable
period of time. If another frame with the same source MAC address does not
arrive at the switch before that time period expires, the MAC entry is aged
(deleted) from the table.
When a frame arrives at the switch, the switch searches for a corresponding or
matching destination MAC address entry in the static or dynamic table. If a match
is found, the frame is marked for egress on the port specified in the table. If frames
are sent to a MAC address that is not found in the tables, they are transmitted or
broadcast to all ports on the relevant VLAN. Such frames are referred to as
unknown Unicast frames.
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