D-Link DES-3326SR User Manual page 73

DES-3326SR Layer 3 Fast Ethernet Switch User's Guide
The part of the IP address that belongs to the network is the
part that is 'hidden' by the '1's in the subnet mask. This can
be seen below:
•
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,
so the Network part of the address (called the Network Address)
is the first octet (10.x.x.x). The node part of the address is the
last three octets (x.42.73.210).
To specify the network address for a given IP address, the node
part 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 part is set
to all "1"s, the address specifies a broadcast address.
10.255.255.255 is the broadcast address for the network
10.0.0.0.
Subnet Masking
A subnet mask can be applied to an IP address to identify the
network and the node parts of the address. A bitwise logical
AND operation between the IP address and the subnet mask
results in the Network Address.
For example:
00001010.00101010.01001001.11010010
Class A IP address
11111111.00000000.00000000.00000000
Class A Subnet Mask
00001010.00000000.00000000.00000000
Network Address
The Default subnet masks are:
10.42.73.210
255.0.0.0
10.0.0.0
61
So,