Enabling Port Security - Cisco Catalyst 2950 Software Manual

Enabling Port Security

Beginning in privileged EXEC mode, follow these steps to define a port as a protected port:
Command
Step 1
configure terminal
Step 2
interface interface
Step 3
switchport protected
Step 4 end
Step 5
show interfaces switchport
Use the no version of the switchport protected interface configuration command to disable the
protected port option.
Enabling Port Security
Secured ports restrict a port to a user-defined group of stations. When you assign secure addresses to a
secure port, the switch does not forward any packets with source addresses outside the defined group of
addresses. If you define the address table of a secure port to contain only one address, the workstation
or server attached to that port is guaranteed the full bandwidth of the port. As part of securing the port,
you can also define the size of the address table for the port.
Port security can only be configured on static access ports.
Note
Secured ports generate address-security violations under these conditions:
•
•
Limiting the number of devices that can connect to a secure port has these advantages:
•
•
These options validate port security or show security violations:
Interface
Security
Trap
Shutdown Port
Secure Addresses
Max Addresses
Security Rejects
Catalyst 2950 Desktop Switch Software Configuration Guide
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The address table of a secured port is full, and the address of an incoming packet is not found in the
table.
An incoming packet has a source address assigned as a secure address on another port.
Dedicated bandwidth—If the size of the address table is set to 1, the attached device is guaranteed
the full bandwidth of the port.
Added security—Unknown devices cannot connect to the port.
Port to secure.
Enable port security on the port.
Issue a trap when an address-security violation occurs.
Disable the port when an address-security violation occurs.
Number of addresses in the secure address table for this port. Secure ports have
at least one address.
Number of addresses that the secure address table for the port can contain.
Number of unauthorized addresses seen on the port.
Purpose
Enter global configuration mode.
Enter interface configuration mode, and enter the port to be
configured.
Enable protected port on the port.
Return to privileged EXEC mode.
Verify that the protected port option is enabled.
Chapter 10 Configuring the Switch Ports
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