Information Technology Reference
In-Depth Information
8
CHAPTER
Troubleshooting Novell IPX
NetWare is a network operating system (NOS) and related support services environment created by
Novell, Inc., and introduced to the market in the early 1980s. Then, networks were small and
predominantly homogeneous, local-area network (LAN) workgroup communication was new, and the
idea of a personal computer (PC) was just becoming popular.
Much of NetWare's networking technology was derived from Xerox Network Systems (XNS), a
networking system created by Xerox Corporation in the late 1970s.
By the early 1990s, NetWare's NOS market share had risen to between 50 percent and 75 percent. With
more than 500,000 NetWare networks installed worldwide and an accelerating movement to connect
networks to other networks, NetWare and its supporting protocols often coexisted on the same physical
channel with many other popular protocols, including TCP/IP, DECnet, and AppleTalk. Although
networks today are predominately IP, there are some legacy Novel IPX traffic.
Novell Technology Basics
As an NOS environment, NetWare specifies the upper five layers of the OSI reference model. The parts
of NetWare that occupy the upper five layers of the OSI model are as follows:
•
NetWare Core Protocol (NCP)
•
Service Advertisement Protocol (SAP)
•
Routing Information Protocol (RIP)
NetWare provides file and printer sharing, support for various applications such as electronic mail
transfer and database access, and other services. Like other NOSs, such as the network file system (NFS)
from Sun Microsystems, Inc., and Windows NT from Microsoft Corporation, NetWare is based on a
client/server architecture. In such architectures, clients (sometimes called workstations) request certain
services such as file and printer access from servers.
Originally, NetWare clients were small PCs, whereas servers were slightly more powerful PCs. As
NetWare became more popular, it was ported to other computing platforms. Currently, NetWare clients
and servers can be represented by virtually any kind of computer system, from PCs to mainframes.
A primary characteristic of the client/server system is that remote access is transparent to the user. This
is accomplished through remote procedure calls, a process by which a local computer program running
on a client sends a procedure call to a remote server. The server executes the remote procedure call and
returns the requested information to the local computer client.
Figure 8-1 illustrates a simplified view of NetWare's best-known protocols and their relationship to the
OSI reference model. With appropriate drivers, NetWare can run on any media-access protocol. The
figure lists those media-access protocols currently supported with NetWare drivers.
