Cisco CATALYST 2960 - Understanding DHCP-based Autoconfiguration and Image Update; You can use the DHCP image upgrade features to configure a DHCP server to download both a new image and a new configuration file to one or more switches in a network. This helps ensure that each new switch added to a network receives the same image and configuration.; DHCP Autoconfiguration; DHCP autoconfiguration downloads a configuration file to one or more switches in your network from a DHCP server. The downloaded configuration file becomes the running configuration of the switch. It does not over write the bootup configuration saved in the flash, until you reload the switch.

2-61
Catalyst 2960 Switch Command Reference
78-16882-01
Chapter 2 Catalyst 2960 Switch Cisco IOS Commands
deny (MAC access-list configuration)
Usage Guidelines You enter MAC-access list configuration mode by using the mac access-list extended global
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, see the software configuration guide 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 Description
mac access-list extended Creates an access list based on MAC addresses for non-IP traffic.
permit (MAC access-list
configuration)
Permits non-IP traffic to be forwarded if conditions are matched.
show access-lists Displays access control lists configured on a switch.