Creating Mac Access Groups - Cisco 2950G 24 - Catalyst Switch Software Configuration Manual

Chapter 25 Configuring Network Security with ACLs
This example shows how to create and display an access list named mac1, denying only EtherType
DECnet Phase IV traffic, but permitting all other types of traffic.
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 Gigabit Ethernet interface 0/1 to filter packets entering the
interface:
Switch(config)# interface gigabitethernet0/1
Router(config-if)# mac access-group 2 in
Note The mac access-group interface configuration command is only valid when applied to a Layer 2
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.
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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.
Catalyst 2950 Desktop Switch Software Configuration Guide
Configuring ACLs
25-19