An administrator has connected devices to a switch and, for security reasons, wants the
dynamically learned MAC addresses from the address table added to the running configuration.
What must be done to accomplish this?
A.
Enable port security and use the keyword sticky.
B.
Set the switchport mode to trunk and save the running configuration.
C.
Use the switchport protected command to have the MAC addresses added to the configuration.
D.
Use the no switchport port-security command to allow MAC addresses to be added to the
configuration.
Port security provides an easy way to discover the MAC addresses used off each port using a feature called sticky secure MAC addresses. With this feature, port security learns the MAC addresses off each port and stores those in the port security configuration (in the running-config file). This feature helps reduce the big effort of
finding out the MAC address of each device.
With sticky learning, you do not need to predefine the specific MAC addresses either. However, you must enable port security, which requires the switchport port-security
interface subcommand.
switch mode access
switchport port-security
^ does not record the mac add, just turn it off
(config)#int fa0/10
(config-if)#switchport port-security maximum 1
(config-if)#switchport port-security mac-address sticky
end
now when a new device is connected, the mac address is stuck on… only maximum life of one mac address
show port-security int fa0/10
^ shows the config of port security
A media access control address (MAC address), also called physical address, is a unique identifier assigned to network interfaces for communications on the physical network segment. MAC addresses are used as a network address for most IEEE 802 network technologies, including Ethernet and WiFi. Logically, MAC addresses are used in the media access control protocol sublayer of the OSI reference model.
MAC addresses are most often assigned by the manufacturer of a network interface controller (NIC) and are stored in its hardware, such as the card’s read-only memory or some other firmware mechanism. If assigned by the manufacturer, a MAC address usually encodes the manufacturer’s registered identification number and may be referred to as the burned-in address (BIA).
It may also be known as an Ethernet hardware address (EHA), hardware address or physical address. This can be contrasted to a programmed address, where the host device issues commands to the NIC to use an arbitrary address.
A network node may have multiple NICs and each NIC must have a unique MAC address.
MAC addresses are formed according to the rules of one of three numbering name spaces managed by the Institute of Electrical and Electronics Engineers (IEEE): MAC-48, EUI-48, and EUI-64. The IEEE claims trademarks on the names EUI-48[1] and EUI-64,[2] in which EUI is an abbreviation for Extended Unique Identifier.
STICKY – to dynamically associates the mac-address to the port. Without the sticky option, the mac-address association goes away after a specified period of time.