Lucent Technologies PortMaster - Manual (Page 300)

Network Addressing
A-4 PortMaster Configuration Guide
Class C Addresses
The class C IP address format allocates the highest 24 bits to the network field and sets
the three highest-order bits to 1, 1, and 0, providing a range from 192 through 223,
inclusive. The remaining 8 bits form the host field. More than two million class C
networks can exist, and each class C network can have up to 254 hosts. For example:
Class D Addresses
The class D IP address format was designed for multicast groups, as discussed in
RFC 988. In class D addresses, the 4 highest-order bits are set to 1, 1, 1, and 0, providing
a range from 224 through 239, inclusive.
Class D addresses are currently used primarily for the multicast backbone (MBONE) of
the Internet. Many routers, including those from Lucent, do not support MBONE or
multicast and therefore ignore class D addresses.
Class E Addresses
The class E IP address is reserved for future use. In class E addresses, the 4 highest-order
bits are set to 1, 1, 1, and 1. Routers currently ignore class E IP addresses.
192.168.20.220
Network
address
Host address