Chapter 9
| General Security Measures
Port Security
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Port Security
These commands can be used to enable port security on a port.
When MAC address learning is disabled on an interface, only incoming traffic with
source addresses already stored in the dynamic or static address table for this port
will be authorized to access the network.
When using port security, the switch stops learning new MAC addresses on the
specified port when it has reached a configured maximum number. Only incoming
traffic with source addresses already stored in the dynamic or static address table
for this port will be authorized to access the network. The port will drop any
incoming frames with a source MAC address that is unknown or has been
previously learned from another port. If a device with an unauthorized MAC
address attempts to use the switch port, the intrusion will be detected and the
switch can automatically take action by disabling the port and sending a trap
message.
mac-learning
This command enables MAC address learning on the selected interface. Use
the
no
form to disable MAC address learning.
Syntax
[
no
]
mac-learning
Default Setting
Enabled
Command Mode
Interface Configuration (Ethernet or Port Channel)
Command Usage
◆
The
no mac-learning
command immediately stops the switch from
learning new MAC addresses on the specified port or trunk. Incoming
traffic with source addresses not stored in the static address table, will be
flooded. However, if a security function such as 802.1X or DHCP snooping
Table 49: Management IP Filter Commands
Command
Function
Mode
Maps a static address to a port in a VLAN
GC
Enables MAC address learning on the selected
physical interface or VLAN
IC
Configures a secure port
IC
Displays entries in the bridge-forwarding database
PE
Displays port security status and secure address count
PE