Tcp/Ip Configuration; Ip Subnet Mask - D-Link DI-106 Series User Manual

TCP/IP Configuration

This chapter shows you how to configure your DI-106 or
DI-106M for TCP/IP. Depending on your particular
applications, you will need to configure different menus. For
instance, Internet access is the most common application of
TCP/IP. For this application, you should configure menu 4. We
will illustrate the configuration for other applications in the
following sections.

IP Subnet Mask

A subnet mask is a 32-bit quantity that, when logically ANDed with
an IP address, yields the network number. For instance, the subnet
masks for class A, B and C networks without subnetting are
255.0.0.0, 255.255.0.0 and 255.255.255.0, respectively.
To create more network numbers, you shift some bits from the host
ID to the network ID. For instance, to partition a class C network
number 192.68.135.0 into two, you shift 1 bit from the host ID to
the network ID. Thus the new subnet mask will be
255.255.255.128; the first subnet will have network number
192.68.135.0 with hosts 192.68.135.1 to 129.68.135.126 and the
second subnet will have network number 192.68.135.128 with
hosts 192.68.135.129 to 192.68.135.254.
It is recommended that you use the same subnet mask for all
physical networks that share an IP network number. The table
below lists the additional subnet mask bits in dot decimal notations.
To use to following table, write down the original subnet mask and
substitute the higher order 0s with the dot decimal of the additional
TCP/IP Configuration 79