D-Link DES-3326 User Manual - page 85
DES-3326 Layer 3 Fast Ethernet Switch User’s Guide
Switch Management and Operating Concepts
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So there are three classes available for the classed IP addressing
scheme. The classed IP addresses are divided into the network
part and the node (end station) part:
•
Class A NETWORK.node.node.node
•
Class B NETWORK.NETWORK.node.node
•
Class C NETWORK.NETWORK.NETWORK.node
For example, the IP address 10.42.73.210 is a Class A address (the
first number is between 1 and 126), so the first octet (10) belongs to
the network, and the remaining three octets belong to the node
(42.73.210). Since these numbers are not valid IP addresses, some
rules have been developed to make valid (and unique) IP addresses
from the network and note part of an IP address.
To specify the network address that corresponds to 10.42.73.210,
the first octet – 10 is made into a valid IP address by adding three
octets of zeros to give a network address of 10.0.0.0. This method
is followed for all classes of a classed subnet.
Additional IP addresses for the subnetwork can be similarly
determined. When the remaining octets are set to all binary ones,
the broadcast address for the subnetwork is specified. For our
example, 10.255.255.255 would be the broadcast address for the
subnetwork (remember that eight 1’s in binary form is 255 in
decimal form).
Note that for Class C networks, only the last octet is set to zeros for
the network address, and all ones for the broadcast address. For
Class B networks, the last two octets are set to zeros for the
network address and all ones for the broadcast address.
To specify the network address for a given IP address, the node
section is set to all “0”s. In our example, 10.0.0.0 specifies the
network address for 10.42.73.210. When the node section is set to
all “1”s, the address specifies a broadcast address that is sent to all
hosts on the network. So, 10.255.255.255 is the broadcast address
for the network 10.0.0.0. Note that for a Class C networks, only