ACL Editor on Cisco IOS
The Access-List (ACL) editor is a configuration mode in the CLI of a Cisco IOS device that allows you to create a new ACL or to edit an existing one. Its advantages include the ability to add, remove, and reorder statements within an ACL using sequence numbers.
You can enter the configuration mode of the ACL editor using the following command:
R2(config)#ip access-list extended 100 R2(config-ext-nacl)#
Or you can do this instead:
R2(config)#ip access-list standard 50 R2(config-std-nacl)#
As you can see, both standard and extended access lists can be configured. Make sure that you use the correct access list number range for the appropriate type of access list used (standard/extended). Otherwise an error message will appear.