In the previous Netguru article, I discussed TCP/IP.
IPX was designed by Novell and is a derivative of
an older networking protocol by XEROX called XNS. IPX has turned
into one of the most prominent network protocols, primarily due
to the shear volume of Novell NetWare LANs installed the world
over. In addition, IBM, Microsoft, LANtastic and other lesser
known NOSs have designed their systems so that IPX could be used
in addition to their own proprietary protocols.
IPX uses an 8 digit, hexadecimal numbering system,
where any numbers between 00000001-FFFFFFFE are valid. Each network
segment is assigned a number by the network engineer or system
administrator. Each network segment must have a unique number,
and no two network segments that are connected in way can have
the same number. Occasionally, you'll find IPX network numbers
forming names, such as: da11a5, f005ba11, badf00d and many others.
The IPX address of an individual device is the IPX
segment address appended with the NIC MAC address, in the form
Every NIC in a file server that has workstations
connected to the same hub, switch or router is a network segment.
In the case of a NetWare based file server, even the OS internally
has an IPX segment number assigned to it, even though no actual
devices communicate on the internal interface. This internal segment
address deals with server to server communications.
Although IPX is a very robust and fast performing
protocol on a LAN, it does have a bit of a performance issue when
traveling over slower speed WAN links, it does slow down and incurs
extra overhead. Novell designed an additional protocol called
Packet Burst, optimized for use when communicating over WAN links.
NetBIOS is the primary protocol used by IBM LANs.
IBM designed the protocol for their original network operating
system, but it was designed in the days of small networks and
is not a fast nor extensible protocol. NetBIOS is not routable,
therefore if multiple networks need to connect together, there
are only a few options. The networks either have to be bridged
together, another protocol has to be used by all devices on all
networks, or a special form of moving the NetBIOS information
must be used - called "tunneling".
Although still in use by IBM based networks today,
more network engineers and managers are opting for more easily
deployable protocols like TCP/IP or IPX. One benefit however is
that NetBIOS has no numbering or naming convention that has to
be configured. All the devices on the network simply use the MAC
address of the NICs in order to communicate together.
NetBEUI was designed by Microsoft and is their primary
protocol for their NOSs. NetBEUI is a derivative of NetBIOS and
follows the same basic operations and pitfalls. More than anything
else, Microsoft wanted the same basic operation of NetBIOS, but
needed a few more capabilities that NetBIOS didn't have. Unfortunately,
NetBEUI is also not routable which has presented many network
engineers and managers with formidable issues of late. Again,
if multiple networks need to connect together, there are only
a few options. The networks either have to be bridged together,
another protocol has to be used by all devices on all networks,
or a special form of moving the NetBEUI information must be used
- called "tunneling".
Some router vendors provide tunneling capabilities
for NetBIOS or NetBEUI protocols in their products. The basic
function of tunneling is taking the initial NetBEUI or NetBIOS
protocol based packet the router port receives, wrapping it an
IP packet, providing the "from" and "to" router
port addresses in the new IP packet, and then the router sends
it on. The receiving router port takes the packet, notices that
it has a special signature, decrypts the embedded NetBEUI or NetBIOS
packet inside and then sends it on in that native format. Unfortunately,
there is some overhead to this function, but if you really need
to "route" these two protocols, it is possible.
Networking capability has been engineered into all
Apple Computer products since the very first Macintosh. However,
Apple wanted the networking of their computers to be inexpensive
compared to other computer and networking products available during
those times (1984). Apple engineered a new protocol called AppleTalk.
AppleTalk has three basic numbering components: the
network address which uses numbers between 0-65535, the node address
using 0-255 and the socket address (used by applications) using
0-255. Additionally, there is the capability of assigning a alphanumeric
name to a network address range or group of network address ranges,
called the Zone Name.
There have been two major releases of AppleTalk,
the original referred to as AppleTalk Phase I, and in 1990 Apple
released AppleTalk Phase II. AppleTalk Phase II supported larger
networks and more sophisticated AppleTalk routing capabilities.
As networking technology advanced, Apple started supporting TCP/IP
and IPX on their computers.
IP Internet Protocol
IPX Internet Packet eXchange
NetBEUI NetBIOS Extended User Interface
NetBIOS Network Basic Input/Output System
NIC Network Interface Card
NOS Network Operating System
TCP/IP Internet Protocol/Transmission Control Protocol
WAN Wide Area Network
XNS XEROX Network Services (protocol)
Copyright © 1997 Jeffrey L. Carrell. All Rights Reserved.
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