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Catalyst 2950 Desktop Switch Software Configuration Guide
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Chapter 24 Configuring Network Security with ACLs
Configuring ACLs
Creating a Numbered Standard ACL
Note For information about creating ACLs to apply to a management interface, refer to the “Configuring IP
Services” section of the Cisco IOS IP and IP Routing Configuration Guide and the Command Reference
for IOS Release 12.1. You can these apply these ACLs only to a management interface.
Beginning in privileged EXEC mode, follow these steps to create a numbered standard IP ACL:
Use the no access-list access-list-number global configuration command to delete the entire ACL. You
cannot delete individual ACEs from numbered access lists.
Note When creating an ACL, remember that, by default, the end of the ACL contains an implicit deny
statement for all packets that it did not find a match for before reaching the end. With standard access
lists, if you omit the mask from an associated IP host address ACL specification, 0.0.0.0 is assumed to
be the mask.
Command Purpose
Step 1
configure terminal Enter global configuration mode.
Step 2
access-list access-list-number {deny | permit |
remark} {source source-wildcard | host source
| any}
Define a standard IP ACL by using a source address and wildcard.
The access-list-number is a decimal number from 1 to 99 or 1300
to 1999.
Enter deny or permit to specify whether to deny or permit access
if conditions are matched.
The source is the source address of the network or host from which
the packet is being sent:
• The 32-bit quantity in dotted-decimal format.
• The keyword any as an abbreviation for source and
source-wildcard of 0.0.0.0 255.255.255.255. You do not need
to enter a source wildcard.
• The keyword host as an abbreviation for source and
source-wildcard of source 0.0.0.0.
(Optional) The source-wildcard applies wildcard bits to the
source. (See first bullet item.)
Note The log option is not supported on the switches.
Step 3
end Return to privileged EXEC mode.
Step 4
show access-lists [number | name] Show the access list configuration.
Step 5
copy running-config startup-config (Optional) Save your entries in the configuration file.