Specifications

D-1

Cisco Security Appliance Command Line Configuration Guide

OL-6721-01

APPENDIX

Addresses, Protocols, and Ports

This appendix provides a quick reference for IP addresses, protocols, and applications. This appendix

includes the following sections:

• IPv4 Addresses and Subnet Masks, page D-1

• IPv6 Addresses, page D-5

• Protocols and Applications, page D-11

• TCP and UDP Ports, page D-12

• Local Ports and Protocols, page D-14

• ICMP Types, page D-15

IPv4 Addresses and Subnet Masks

This section describes how to use IPv4 addresses in the security appliance. An IPv4 address is a 32-bit

number written in dotted-decimal notation: four 8-bit fields (octets) converted from binary to decimal

numbers, separated by dots. The first part of an IP address identifies the network on which the host

resides, while the second part identifies the particular host on the given network. The network number

field is called the network prefix. All hosts on a given network share the same network prefix but must

have a unique host number. In classful IP, the class of the address determines the boundary between the

network prefix and the host number.

This section includes the following topics:

• Classes, page D-2

• Private Networks, page D-2

• Subnet Masks, page D-2