TDT RZ2, Manual

Page: 72 / 736

1-66 System 3
RZ-UDP Communications Interface
Network Address
All network devices utilize a network address commonly referred to as the “IP
address”. The IP address is a unique address given to any networked device and
consists of four hexadecimal values that are used to locate a device from within a
network. Multiple devices that are located within a common network use similar IP
addresses.
For example:
Several office computers are connected to a network within an office.
IP address Computer 1:192.86.100.10
IP address Computer 2:192.86.100.11
IP address Computer 14:192.86.100.23
As shown above, IP addresses share a common prefix when located on a common
network.
Subnet Mask
Just as the IP address is important for each device contained within a network, the
subnet mask is used to classify the size of the network as well as determine the
broadcasting address for a device. When an IP address is given to a device, the
inverse of the subnet mask is ORed to the IP address to obtain the broadcast
address.
For example:
To obtain the broadcast for an IP address with a subnet mask of 255.255.255.0
the IP address and inverse of the subnet mask value are ORed.
IP Address:
192.86.100.10 = 1100 0000 | 0101 0110 | 0110 0100 | 0000 1010
Subnet Mask
-1
:
0.0.0.255 = 0000 0000 | 0000 0000 | 0000 0000 | 1111 1111
Broaast:
192.86.100.255 = 1100 0000 | 0101 0110 | 0110 0100 | 1111 1111
Several types of network protocols and services use broadcasts in different ways.
Dynamic Host Configuration Protocol (DHCP), for instance, requires that broadcasts
be used to dynamically assign a unique IP address to computers on a network.
Types of Networks
Several different classifications of networks exist and are organized by the number of
possible network addresses (IP addresses) available. The previous example used a
Class C network subnet mask.
The following table illustrates the bit ranges and classifications of common networks.
Class Start End Default Subnet Mask
Class A 0.0.0.0 127.255.255.255 255.0.0.0
Class B 128.0.0.0 191.255.255.255 255.255.0.0