Technicolor - Thomson 210i - Manual (Page 74)

SpeedTouch 210i
70
different for each IP device — or, to be more precise, each IP-capable port or
interface — connected directly to that network.
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 Internet-assigned
network number, you must obtain a registered IP network number from an Internet-
authorized network information center. In many countries you must apply through a
government agency, however they can usually be obtained from your Internet Service
Provider (ISP).
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.