2.1.a Implement and troubleshoot switch administration

2.1.a [i] Managing MAC address table

By default, MAC address learning is enabled on all interfaces and VLANs and MAC address aging is set to 300 seconds on a Cisco switch. You can control MAC address learning on an interface or VLAN to manage the available MAC address table space. Before you disable MAC address learning, be sure that you are familiar with the overall environment which includes network topology and the router system configuration. Disabling MAC address learning on an interface or VLAN could cause flooding in the network. You can disable MAC address learning on a single VLAN ID from 1 to 4094 (for example, no mac address-table learning vlan 229) or a range of VLAN IDs, separated by a hyphen or comma (for example, no mac address-table learning vlan 1-100, 16).

You can display the MAC address table by using one or more of the privileged EXEC commands.

show mac address-table address – Displays MAC address table information for the specified MAC address.

show mac address-table aging-time – Displays the aging time in all VLANs or the specified VLAN

Adam, Paul (2014-07-12). All-in-One CCIE V5 Written Exam Guide (Kindle Locations 1468-1471).  . Kindle Edition.

http://www.cisco.com/c/en/us/td/docs/wireless/mwr_2941_dc/software_config/guide/3_3/2941_33_Config_Guide/mac_lrn.pdf

show mac address-table address        Displays MAC address table information for the
specified MAC address.

show mac address-table aging-time    Displays the aging time in all VLANs or the specified VLAN

show mac address-table count            Displays the number of addresses present in all VLANs or  the specified VLAN

show mac address-table dynamic       Displays only dynamic MAC address table entries

show mac address-table interface      Displays the MAC address table info rmation for the specified interface

show mac address-table learning       Displays MAC address learning status of all VLANs or the specified VLAN

show mac address-table static            Displays only static MAC address table entries

show mac address-table vlan              Displays the MAC address table in formation for the specified VLAN

sh mac address-table