Wavetronix Click 342 (lean managed ethernet switch) (CLK-342) - Managed Switches User Guide - Manual (Page 16)

CHAPTER 1 • CLICK 340/341/342 MANAGED SWITCHES 15
switch.
Assigning IP Addresses
The IP address is a 32-bit address, which consists of a network part and a user part. The
network part consists of the network class and the network address (see Figure 2.1).
Figure 2.1 – Position of Bits Within the IP Address
There are currently five defined network classes; Classes A, B and C are used in modern
applications, while Classes D and E are used rarely. It is therefore usually sufficient if a net-
work device only recognizes Classes A, B and C.
With binary representation of the IP address the network class is represented by the first
bits. The key factor is the number of “ones” before the first “zero.” The assignment of classes
is shown in the following table (see Table 2.1). The empty cells in the table are not relevant
to the network class and are already used for the network address.
Bit 1 Bit 2 Bit 3 Bit 4 Bit 5
Class A 0
Class B 1 0
Class C 1 1 0
Class D 1 1 1 0
Class E 1 1 1 1 0
Table 2.1 – Assignment of Classes
The bits for the network class are followed by those for the network address and the user ad-
dress (see Table 2.2). Depending on the network class, a different number of bits are avail-
able, both for the network address (network ID) and the user address (host ID).
Network ID Host ID
Class A 7 bits 24 bits
Class B 14 bits 16 bits
Class C 21 bits 8 bits
Class D 28-bit multicast identifier
Class E 27 bits (reserved)
Table 2.2 – Bits for the Network and User Addresses