GLOSSARY
In a Class A network, the first of the numbers is the network number, the last three numbers are the local host address.
In a Class B network, the first two numbers are the network, the last two are the local host address.
In a Class C network, the first three numbers are the network address, the last number is the local host address.
The following table summarizes the classes and sizes:
Class | First # | Max# Hosts |
A | 16,387,064 | |
B | 64,516 | |
C | 254 |
Network mask values are used to identify the network portion and the host portion of the address. For:
Class A - the default mask is 255.0.0.0
Class B - the default mask is 255.255.0.0
Class C - the default mask is 255.255.255.0
Subnet masking is used when a portion of the host ID is used to identify a subnetwork. For example, if a portion of a Class B network address is used for a subnetwork, the mask could be set as 255.255.255.0. This would allow the third byte to be used as a subnetwork address. All hosts on the network would still use the IP address to get on the Internet.
IP (Internet Protocol) - a connectionless,
IPX Protocol (Internetwork Packet Exchange) - a NetWare protocol similar to the Xerox Network Systems (XNS) protocol that provides datagram delivery of messages.
IS (Intermediate system) - a system that provides forwarding functions or relaying functions or both for a specific ATM connection. OAM cells may be generated and received.
ISA Bus - a bus standard developed by IBM for expansion cards in the first IBM PC. The original bus supported a data path only 8 bits wide. IBM subse- quently developed a
