Private ip addresses – ZyXEL Communications ZyXEL Dimension ES-2108 User Manual

Page 270

Advertising
background image

ES-2108 Series User’s Guide

270

Appendix B IP Addresses and Subnetting

Private IP Addresses

Every machine on the Internet must have a unique address. If your networks are isolated from
the Internet (running only between two branch offices, for example) you can assign any IP
addresses to the hosts without problems. However, the Internet Assigned Numbers Authority
(IANA) has reserved the following three blocks of IP addresses specifically for private
networks:

• 10.0.0.0 — 10.255.255.255
• 172.16.0.0 — 172.31.255.255
• 192.168.0.0 — 192.168.255.255

You can obtain your IP address from the IANA, from an ISP, or it can be assigned from a
private network. If you belong to a small organization and your Internet access is through an
ISP, the ISP can provide you with the Internet addresses for your local networks. On the other
hand, if you are part of a much larger organization, you should consult your network
administrator for the appropriate IP addresses.

Regardless of your particular situation, do not create an arbitrary IP address; always
follow the guidelines above. For more information on address assignment, please
refer to RFC 1597, Address Allocation for Private Internets and RFC 1466, Guidelines
for Management of IP Address Space.

Advertising