Cisco Catalyst 3550 Command Reference Manual page 92

deny
Usage Guidelines
You enter MAC-access list configuration mode by using the
configuration command.
If you use the host keyword, you cannot enter an address mask; if you do not use the host keyword, you
must enter an address mask.
When an access control entry (ACE) is added to an access control list, an implied deny-any-any
condition exists at the end of the list. That is, if there are no matches, the packets are denied. However,
before the first ACE is added, the list permits all packets.
For more information about named MAC extended access lists, refer to the software configuration guide
Note
for this release.
Examples
This example shows how to define the named MAC extended access list to deny NETBIOS traffic from
any source to MAC address 00c0.00a0.03fa. Traffic matching this list is denied.
Switch(config-ext-macl)# deny any host 00c0.00a0.03fa netbios.
This example shows how to remove the deny condition from the named MAC extended access list:
Switch(config-ext-macl)# no deny any 00c0.00a0.03fa 0000.0000.0000 netbios.
This example denies all packets with Ethertype 0x4321:
Switch(config-ext-macl)# deny any any 0x4321 0
You can verify your settings by entering the show access-lists privileged EXEC command.
Related Commands Command
mac access-list extended
permit
show access-lists
Catalyst 3550 Multilayer Switch Command Reference
2-66
mac access-list extended
Description
Creates an access list based on MAC addresses for non-IP traffic.
Permits non-IP traffic to be forwarded if conditions are matched.
Displays access control lists configured on a switch.
Chapter 2 Cisco IOS Commands
global
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