Standard and extended ACLs can be created using either a number or a name to identify the ACL and its list of statements.

Using numbered ACLs is an effective method for determining the ACL type on smaller networks with more homogeneously defined traffic. However, a number does not provide information about the purpose of the ACL. For this reason, starting with Cisco IOS Release 11.2, a name can be used to identify a Cisco ACL.

The figure summarizes the rules to follow to designate numbered ACLs and named ACLs.

Regarding numbered ACLs, numbers 200 to 1299 are skipped because those numbers are used by other protocols, many of which are legacy or obsolete. This course focuses only on IP ACLs. Examples of legacy ACL protocol numbers are 600 to 699 used by AppleTalk, and numbers 800 to 899 used by IPX.