|  | 1.5 | Access List Overview
| 1.5.4 | How to identify access lists
Access lists can control traffic for most protocols on a Cisco router. The Figure shows the protocols and number ranges of the access list types. An administrator enters a number in the protocol number range as the first argument of the global access list statement. The router identifies which access list software to use based on this numbered entry. Access list test conditions follow as arguments. These arguments specify tests according to the rules of the given protocol suite. The meaning or validity of the standard and extended identification scheme for access lists varies by protocol. Many access lists are possible for a protocol. A different number must be selected from the protocol number range for each new access list. Keep in mind, though, that only one access list can be specified per protocol, per interface, per direction. NOTE: With Cisco IOS Release 11.2 and later you can also identify a standard or extended IP access list with an alphanumeric string (name) instead of the current numeric (1 to 199) representation. This can be an easier identification method to administer. Named IP access lists provide other advantages covered later in this chapter.