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Catalyst 2900 Series XL and Catalyst 3500 Series XL Software Configuration Guide
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Chapter 6 Configuring the System
Managing the MAC Address Tables
Managing the MAC Address Tables
You can manage the MAC address tables that the switch uses to forward traffic between ports. All MAC
addresses in the address tables are associated with one or more ports. These MAC tables include these
types of addresses:
•
Dynamic address: a source MAC address that the switch learns and then drops when it is not in use.
•
Secure address: a manually entered unicast address that is usually associated with a secured port.
Secure addresses do not age.
•
Static address: a manually entered unicast or multicast address that does not age and that is not lost
when the switch resets.
The address tables list the destination MAC address and the VLAN ID, module, and port number
associated with the address.
Figure 6-5
shows an example list of addresses as they would appear in the
dynamic, secure, or static address table.
Table 6-2
shows the maximum number of MAC addresses
supported on the Catalyst 2900 XL and Catalyst 3500 XL switches.
Figure 6-5
Contents of the Address Table
MAC Addresses and VLANs
All addresses are associated with a VLAN. An address can exist in more than one VLAN and have
different destinations in each. Multicast addresses, for example, could be forwarded to port 1 in VLAN
1 and ports 9, 10, and 11 in VLAN 5.
Each VLAN maintains its own logical address table. A known address in one VLAN is unknown in
another until it is learned or statically associated with a port in the other VLAN. An address can be secure
in one VLAN and dynamic in another. Addresses that are statically entered in one VLAN must be static
addresses in all other VLANs.
Table 6-2
Maximum Number of MAC Addresses Supported
Switch
Maximum Number of MAC Address Supported
Catalyst 2924 XL, 2924C XL, and 2912 XL switches 2048
Catalyst 2924M XL and 2912MF XL switches
8192
Catalyst 2900 LRE XL switches
8192
Catalyst 3500 XL switches
8192