Resuming Normal Forwarding On A Port; Configuring Port Security; Understanding Port Security; Secure Mac Addresses - Cisco Catalyst 2950 Software Configuration Manual

Configuring Port Security

Resuming Normal Forwarding on a Port

Beginning in privileged EXEC mode, follow these steps to resume normal forwarding on a port:
Command
Step 1 configure terminal
Step 2 interface interface-id
Step 3
no switchport block multicast
Step 4 no switchport block unicast
Step 5 end
Step 6
show interfaces interface-id switchport
Step 7
copy running-config startup-config
Configuring Port Security
You can use the port security feature to restrict input to an interface by limiting and identifying MAC
addresses of the stations allowed to access the port. When you assign secure MAC addresses to a secure
port, the port does not forward packets with source addresses outside the group of defined addresses.
This section includes information about these topics:
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Understanding Port Security

This section includes information about:
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Secure MAC Addresses

You can configure these types of secure MAC addresses:
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Catalyst 2950 and Catalyst 2955 Switch Software Configuration Guide
21-6
Understanding Port Security, page 21-6
Default Port Security Configuration, page 21-8
Port Security Configuration Guidelines, page 21-8
Enabling and Configuring Port Security, page 21-9
Enabling and Configuring Port Security Aging, page 21-11
Secure MAC Addresses, page 21-6
Security Violations, page 21-7
Static secure MAC addresses—These are manually configured by using the switchport
port-security mac-address mac-address interface configuration command, stored in the address
table, and added to the switch running configuration.
Dynamic secure MAC addresses—These are dynamically learned, stored only in the address table,
and removed when the switch restarts.
Purpose
Enter global configuration mode.
Specify the interface to configure, and enter interface configuration
mode.
Enable unknown multicast flooding to the port.
Enable unknown unicast flooding to the port.
Return to privileged EXEC mode
Verify your entries.
(Optional) Save your entries in the configuration file.
Chapter 21 Configuring Port-Based Traffic Control
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