DI-304/DI-304M ISDN Remote Router
The network portion of an IP address will be referred to in this manual as a network number; the host portion will be referred to as a host number.
To connect to the Internet or to any private IP network that uses an
If your organization's networks are, and will always remain, a closed system with no connection to the Internet or to any other IP network, you can choose your own network numbers as long as they conform to the above rules.
If your networks are isolated from the Internet, e.g. only between your two branch offices, you can assign any IP Addresses to hosts without problems. However, the Internet Assigned Numbers Authority (IANA) has reserved the following three blocks of IP Addresses specifically for private (stub) networks:
Class | Beginning Address | Ending Address |
A | 10.0.0.0 | 10.255.255.255 |
B | 172.16.0.0 | 172.31.255.255 |
C | 192.168.0.0 | 192.168.255.255 |
It is recommended that you choose private network IP Addresses from the above list. 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.
Subnet Mask
In the absence of subnetworks, standard TCP/IP addressing may be used by specifying subnet masks as shown below.
IP Class | Subnet Mask |
Class A | 255.0.0.0 |
Class B | 255.255.0.0 |
Class C | 255.255.255.0 |
Subnet mask settings other than those listed above add significance to the interpretation of bits in the IP address. The bits of the subnet mask correspond directly to the bits of the IP address. Any bit an a subnet mask that is to correspond to a net ID bit in the IP address must be set to 1.
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