Working with extended ACLs

Extended ACLs are sometimes the preferred choice as they allow you to filter specific traffic types compared to standard ACLs. Extended ACLs use the following range of numbers:

• 100 to 199
• 2000 to 2699

To create a numbered extended ACL on a Cisco IOS router, use the global configuration access-lists command, followed by a number within the range of 100 to 199 or 2000 to 2699 on the device.

Creating a numbered extended ACL

The following is the full syntax used to create a numbered extended ACL:

Router(config)# access-list access-list-number [ deny | permit | remark ] protocol [source source-wildcard] [operator port] [port-number or name] [destination destination-wildcard] [operator port] [port-number or name]

The following is a description of the new syntax used within an extended ACL:

• protocol: Specifies the protocol type, such as IP, ICMP, TCP, and UDP.
• operator: Used to compare the source or destination ports....