The critical nature of protocols demands that you spend a few minutes studying the protocols that can make or break your network.
Windows 2000 Diplomacy: Key Protocols
The critical nature of protocols demands that you spend a few minutes studying the protocols that can make or break your network.
Where else in the world of Windows 2000 could you speak
about world politics? Huh? Hear me out on this one. When
I'm wearing my trainer's hat, I often have to resort to
odd examples to convey complex technical points. Protocols,
our subject this month, fit this bill.
Close your eyes and think about world peace for a minute.
The way we achieve world peace is via diplomacy. In the
world of diplomacy, there are behaviors known as diplomatic
protocols that allow people from different lands to communicate
and negotiate. In fact, diplomatic protocols dictate how
messages are delivered between governments. This is analogous
to networks: Networking protocols dictate how messages
are delivered.
Computers of different makes, operating systems, and
geographical locations communicate effectively when they
use an agreed-upon protocol. That's why a Macintosh running
MacTCP can communicate with a Unix workstation running
TCP/IP. It's why a NetWare server running IPX/SPX can
communicate with a Win2K Server running NWLink IPX/SPX.
Back to the geopolitical real world. What happens when
two nations don't have diplomatic relations, such as the
U.S. and Iraq? Typically, a third country has to act as
an intermediary to facilitate communications. The same
thing occurs in Win2K networks. If two hosts are running
separate protocols, communications won't occur. However,
introduce a third-party intermediary known as a gateway
and good things happen. An example of this in the Microsoft
BackOffice family is SNA Server, which runs on Win2K Server.
SNA Server facilitates communications between Win2K and
IBM mid-range and mainframe computers.
Why Learn Protocols?
Networking protocols are an exciting aspect of Win2K
because it's an area where you can really develop some
mastery and add value to the networks you manage. For
example, it seems like the default protocol, TCP/IP, is
infinitely configurable. At times TCP/IP also seems to
be infinitely bedeviling and thus part of the excitement.
NT 4.0 MCSEs will remember all too well the emphasis placed
on TCP/IP with its own certification exam (something that's
been eliminated in the Win2K MCSE track). I've found networking
protocol installation, administration, and troubleshooting
to be the most challenging and rewarding aspects of managing
networks. And Win2K networks are proving to be no exception.
And don't you remember that twinge of excitement the
first time you learned about the middle layers of the
Open Systems Interconnection (OSI) model? Of course, you
do. I've also observed MCSEs, fascinated by the whole
protocol area, go on to study Cisco routers and pursue
Cisco certifications in addition to their MCSE interests.
Networking protocols are fundamental to the understanding
of Win2K. If a protocol is missing, corrupt, or misconfigured,
you've come to the end of the line on your Win2K network.
The critical nature of protocols demands that we spend
a few moments looking at some protocols that will make
or break your network.
Said protocols are best exemplified by looking at Network
Monitor in Win2K. Network Monitor is a tool traditionally
known as a sniffer, which is used to observe network activity
and troubleshoot problems. The key to using Network Monitor
is to know protocols because it indexes everything by
protocol type. In a future month I'll focus on Network
Monitor; but for now Figure 1 provides a glimpse of this
tool.
 |
| Figure 1. Network Monitor showing
packets identified by protocol (TCP and SMB in this
case). |
What Ships with Win2K
Win2K ships with a variety of protocols, including the
following from Microsoft:
- TCP/IP (the default protocol in Win2K)
- NetBEUI
- NWLink IPX/SPX/NetBIOS Compatible Transport Protocol
- DLC
- AppleTalk Protocol
Note that Win2K uses other protocols for very specific
purposes. An example of this is the Simple Network Management
Protocol (SNMP), which includes agents that monitor the
activity of network devices and report this information
to an SNMP-enabled application.
TCP/IP
Ah, TCP/IP, the underlying protocol of modern networks
everywhere, including the Internet. Officially known as
Transmission Control Protocol/Internet Protocol, TCP/IP's
strengths include its routability, and configurability.
Because TCP/IP is routable, which means it can link one
local network to another network, it has been well accepted
as the standard protocol for internetworking. TCP/IP is
also highly configurable, allowing it to be implemented
according to your specific needs. I'll discuss this point
using the next several screen shots.
First, you need to display the properties for the TCP/IP
protocol within Win2K. To do this:
- Right-click on My Network Places on the desktop to
display the secondary menu.
- Select Properties from the secondary menu.
- The Network and Dial-up Connections window will be
displayed. Right-click on the Local Area Connection
icon.
- Select Properties from the secondary menu.
- The Local Area Connection Properties menu appears.
Highlight Internet Protocol (TCP/IP) and click the Properties
button.
- The Internet Protocol (TCP/IP) Properties dialog
box appears, as shown in Figure 2.
 |
| Figure 2. The default settings
for the TCP/IP protocol in Win2K. |
Unlike the other protocols discussed shortly, you must
configure TCP/IP addresses, called IP addresses for short.
You can do this in three ways: with a real Internet address,
with a private network address, and through DHCP. Today,
it's common to implement Win2K using real, Internet-registered
IP addresses. I show this in Figure 3.
 |
| Figure 3. An actual IP address
(Internet-registered) is used to configure the General
tab sheet on the Internet Protocol (TCP/IP) Properties
dialog box. |
You'll receive the IP address information you need from
another network administrator within your company or from
your Internet service provider (ISP). You'll typically
complete each field on the General tab sheet:
- IP address. Where you enter
the IP address. This is a required field.
- Subnet Mask. Where you
enter the Subnet Mask, which really defines the network
class you're participating in. Figure 3 shows a Class
C address. This is an optional field.
- Default Gateway. Typically
the address of a router or a server located at your
ISP's location. This is an optional field on the one
hand (when you're running the computer on a LAN) and
a required entry when you're running the computer on
a WAN or the Internet.
- Preferred and Alternate DNS server.
Typically required fields to facilitate name resolution.
This information is either a DNS server on your network
or the Internet. I discuss DNS in my July 2000 column.
The second way to implement TCP/IP in Win2K is to use
private IP addresses. These addresses aren't registered
on the Internet and look similar to Figure 4.
 |
| Figure 4. Private IP addressing
using the common 10.0.0.x addressing scheme. |
The third means of obtaining an IP address-the default
setting in Win2K-is to acquire it from a DHCP server.
You can see in Figure 4 the "Obtain an IP address
automatically" radio button. I discuss DHCP servers
in my column next month-as well as a few tab sheets exposed
by the Advanced button (DNS and WINS) you see in Figure
4.
NetBEUI
Back in the days when knight were bold and kings owned
all the Microsoft stock options, the preferred protocol
for Microsoft-based networks was NetBEUI. This protocol
is leaner than TCP/IP, not requiring as much in the way
of acknowledgement traffic (and so it was considered faster);
but it couldn't be routed. That wasn't a problem when
the prevailing networking paradigm was the LAN-with an
emphasis on the word "local." However, the world
changed quickly; today's emphasis is now Wide Area Networks
(WANs). And thus came the fall of the NetBEUI kingdom.
Note that NetBEUI isn't a configurable protocol.
So why is NetBEUI still part of Win2K? I can think of
a couple of reasons.
First, there are crafty server farm scenarios whereby
NetBEUI is used for fast communications between some hosts
(say, Win2K servers) on one side of a router. Why? To
take advantage of the fact that NetBEUI is small and efficient
and doesn't have the additional header entries associated
with routing. Because it's in effect faster than TCP/IP
under the right conditions, its use is one way that network
engineers can shave a nano-second here and there.
A second use of NetBEUI in Win2K, quite frankly, is to
use it when nothing else works. For example, if TCP/IP
has gone south on you, try good old NetBEUI to establish
basic connectivity. I did this once at a charity auction
where I set up a small network in a hotel lobby.
NWLink IPX/SPX/NetBIOS Compatible Transport
Protocol
To accommodate the red heads amongst us (NetWare-types),
Microsoft has continued to include its version of IPX/SPX
in order to participate on NetWare networks. To be honest,
it's rare to see homogenous Win2K networks that use NWLink
IPX/SPX (these networks are typically TCP/IP).
DLC
I've used this protocol, which has a way of sneaking
into multiple-choice questions on the MCSE certification
exams, to connect to HP JetDirect cards attached to HP
laser printers. My heavy metal friends from the legacy
community also tell me it's used for mainframe connectivity
(I wouldn't know).
AppleTalk Protocol
Proving the Apple-Microsoft chasm was never so wide it
couldn't support network connectivity, the AppleTalk protocol
is used to support Macs on a Win2K network. For certain
users, including my clients in the printing and advertising
industries, this is a critical need. Win2K networks support
Mac clients in a secure and stable way. The support primarily
exists for network authentication, file storage, and printer
usage. You can't run a native Mac application on a Win2K
Server.
More To Come!
Next month, DNS, DHCP and WINS!