This document summarizes IP access control lists (ACLs), including the syntax for standard and extended ACLs, supported source/destination definitions, TCP/UDP port definitions, options for applying and troubleshooting ACLs. Standard ACLs filter based on source IP address while extended ACLs can also filter based on protocol, source/destination ports, flags, and other options. Numbers, names, sequences and actions (permit, deny) are used to configure individual ACL rules.