ZyXEL Communications 128MH user manual Private IP Adresses, Assigning IP Addresses

Prestige 128MH PSTN Router/Hub

Private IP Adresses

If your networks are isolated from the Internet (for example, only between your two branch offices) you can assign arbitrarily 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, as shown in Table 3-2.

For this reason, it is recommended that you choose your private network number from the list provided in Table 3-3.

Table 3-3. Private Networks IP Addresses

Private IP Addresses

10.0.0.0- 10.255.255.255

172.16.0.0- 172.31.255.255

192.168.0.0 - 192.168.255.255

Assigning IP Addresses

You can obtain your IP address from the IANA, from an ISP, or 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.

Note on IP Address Assignment

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

3-4Chapter 3 Internet Access Application