Understanding Networking Protocols
complex Windowsbased network that also uses TCP/IP, however, the NetBIOS names
resolve to TCP/IP addresses through the use of Windows Internet Name Service
(WINS). The names can also be resolved using static name definition entries contained
in a file called LMHOSTS (for LAN Manager HOSTS).
Because some networking applications still use NetBIOS Names, either WINS or
LMHOSTS allows such applications to continue to function in a TCP/IP-only network.
As far as the application is concerned, it is still working with NetBIOS, while TCP/IP
performs the actual work in the background.
AppleTalk has been extended into AppleTalk Phase 2, which now allows routing of
AppleTalk packets (assuming an AppleTalk Phase 2-capable router). The Phase 2
variant can run over Ethernet, Token Ring, or Apple's LocalTalk media. Under Ethernet,
AppleTalk uses a variant of the 802.2 frame type called Ethernet Subnetwork Access
AppleTalk has an important history for Apple Macintosh networking, but Apple
now fully supports and recommends TCP/IP for its computers.
This chapter is built on the knowledge you gained in earlier chapters, delving into
various important protocols involved in virtually all networks, including the Internet.
You learned primarily about the TCP/IP protocol, which has essentially displaced
older protocols such as IPX/SPX and NetBIOS/NetBEUI (although these older
protocols are still used). You also learned about some specific application-layer Internet
protocols, such as SMTP, DHCP, and HTTP. These are all vital protocols to understand
for any networking professional.
It would be nice if the protocols discussed in this chapter were all you had to contend
with, but, unfortunately, many more protocols exist. Some are specific to certain functions,
such as remote access to a network, and are discussed in appropriate chapters within
this book. Others are still being developed and are not a factor now, but may be in the
near future. You will certainly want to stay up-to-date with emerging protocols that may
become important to networking.
The next chapter is about directory services, which make complex networks easier
to use and administer.