Creating Mac Access Groups; Applying Acls To Terminal Lines Or Physical Interfaces - Cisco Catalyst 2950 Software Configuration Manual

Applying ACLs to Terminal Lines or Physical Interfaces

Switch(config)# mac access-list extended mac1
Switch(config-ext-macl)# deny any any decnet-iv
Switch(config-ext-macl)# permit any any
Switch(config-ext-macl)# end
Switch # show access-list
Extended MAC access list mac1

Creating MAC Access Groups

Beginning in privileged EXEC mode, follow these steps to create MAC access groups and to apply a
MAC access list to an interface:
Command
Step 1
configure terminal
Step 2 interface interface-id
Step 3 mac access-group {name} {in}
Step 4
end
Step 5 show mac-access group
Step 6 copy running-config startup-config
This example shows how to apply ACL 2 on an interface to filter packets entering the interface:
Switch(config)# interface gigabitethernet0/1
Router(config-if)# mac access-group 2 in
The mac access-group interface configuration command is only valid when applied to a Layer 2
Note
interface.
For inbound ACLs, after receiving a packet, the switch checks the packet against the ACL. If the ACL
permits the packet, the switch continues to process the packet. If the ACL rejects the packet, the switch
discards the packet. The MAC ACL applies to both IP and non-IP packets.
When you apply an undefined ACL to an interface, the switch acts as if the ACL has not been applied to
the interface and permits all packets. Remember this behavior if you use undefined ACLs as a means of
network security.
Applying ACLs to Terminal Lines or Physical Interfaces
Before applying an ACL to a physical interface, see the
Note
Interfaces" section on page
Catalyst 2950 and Catalyst 2955 Switch Software Configuration Guide
28-18
deny any any decnet-iv
permit any any
Purpose
Enter global configuration mode.
Identify a specific interface for configuration, and enter interface
configuration mode.
The interface must be a Layer 2 interface.
Control access to the specified interface by using the MAC access list name.
Return to privileged EXEC mode.
Display the MAC ACLs applied on the switch.
(Optional) Save your entries in the configuration file.
28-6.
Chapter 28 Configuring Network Security with ACLs
"Guidelines for Applying ACLs to Physical
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