The
life of an NT systems administrator is fraught with peril. In one location, you
have a rapidly growing network with about 240 client nodes running a combination
of Windows NT 4.0 Workstation, Windows 95, and a few Windows for Workgroups
(WFW) 3.11 machines (you just haven't had the time to standardize, or maybe you
have no choice). You also have six NT 4.0 servers with one Primary Domain
Controller (PDC) and--because you're paranoid--three Backup Domain Controllers
(BDCs) for your single-domain structure (DOMAIN_MAIN), an Exchange server, and a
SQL server. The BDCs also function as your print servers. The six NT servers
contain all network files and necessary resources. The company has standardized
on TCP/IP but has yet to implement routers, so you have decided not to implement
Windows Internet Name Service (WINS) at this time. Because you have a legacy
NetWare server, you are also running IPX/SPX (NWLink). Your users access the
NetWare box using NT's Gateway Services for NetWare, and you plan to phase it
out in the near future.
Boost your network performance by
disabling unnecessary server components and taking charge of the browser
You are steadily replacing the old WFW machines with new hardware running NT
4.0 Workstation (good move). Life used to be good. But over the past few months,
as you've added more nodes to the wire, the system has begun to slow down at
unpredictable times. And to top it all off, every client's Network Neighborhood
(Connect Network Drive in the WFW machines) now lists most of the 240 nodes and
the six NT servers.
Your customers are complaining about several problems: 1) general network
performance is slower than it used to be and getting worse ("Some upgrade!");
2) mapping drives is a pain because the NT servers and the NT clients are all
lumped together in the same list under DOMAIN_MAIN, and the Win95 and WFW
clients are listed in the first screen instead of being grouped in a domain; and
3) every once in a while, for no reason, the entire network slows to a crawl for
what seems like a minute or two, causing timeouts, resends, and ticked-off
users. You are at a loss because you bought high-end hardware and followed all
of Microsoft's default installation instructions. Deep inside, you're certain
that if you don't fix this problem soon, management is going to suggest that you
call a consultant. That possibility is not good in your environment: The
last consultant they called is now the CIO.
But don't despair. Some slowdown in network performance is a result of the
way Microsoft handles network browsing. By making some minor changes in the
server components in your system and disabling the browser, you can recoup some
of your lost performance.
Clients and Servers
To better understand Microsoft's network browsing, let's look briefly at
some of the technology underlying all Microsoft operating systems since WFW 3.1.
I'm oversimplifying a bit, but every Microsoft operating system contains two
major component types that govern network access: a workstation component and a
server component. These components take the form of services in NT, but they
exist in Win95 and WFW, too.
In Win95 and WFW, you can't separate the workstation component from the
product. Each of these products exists simply to be the OS for standalone boxes
or workstations on a network. However, in both NT Workstation and Server, the
workstation component is a separate service that you can manage individually
through the Services applet in Control Panel. The purpose of this service is to
provide the client portion of a client/server connection--that is, to connect to
shared folders and shared printers in a Microsoft network.
The server component creates the capability for a given machine (running
WFW, Win95, LanMan, or NT) to function as a server on the network. Active by
default, this component lets you share directories, folders, and printers so
that clients running the workstation component can connect to the server
machine. On request, Network Neighborhood or Connect Network Drive presents
lists of every computer (grouped by domain or workgroup) that has an active
server component in the Microsoft network, even if a particular computer has
nothing shared (no folders, no printers). By default, the computer's Browser
service (which runs automatically in all Microsoft OSs) manages the creation of
this list.
The Browser
The NT Browser service is designed to give users a dynamically updated list
of available resources (in Network Neighborhood or Connect Network Drive). The
Browser runs under the covers in every Microsoft network.
A master browser runs the Browser service. A master browser is a machine
that acts as a sort of name service that keeps track of all servers that report
themselves to it; it creates and maintains the browse list. A backup browser
receives the browse list from the master browser and sends it to computers that
ask for it. (For more information about browsers, see Mark Minasi, "Domains
and Workgroups," April 1996.)
I’m writing in response to George Spalding’s August article, “Too Many Servers Spoil Network Performance.” What you don’t know can hurt you. I am well acquainted with Microsoft’s method for handling network browsing.<br> My company is headquartered in St. Louis, Missouri. We implemented a new NT server-based corporatewide domain shortly after NT 4.0 came out, and we have WAN links to Florida and to Alvarez, Mexico. Users at both locations are members of the corporate domain, so clients at both remote locations began winning master browser elections.<br> Our link to Florida is 256KB. When machines in Florida served as domain master browser, browsing the Network Neighborhood or opening File Manager or Explorer began taking several minutes to complete. In Mexico, our link is just 56KB, and when a machine there became the domain master browser, the problem was much worse.<br> Machines in St. Louis that were attempting to browse were being routed to a machine in Mexico. Once we had enough machines trying to browse, the pipe to Mexico jammed. At that point, anyone attempting to browse would lock up, regardless of OS. Naturally, we had users rebooting all over the network. We were able to figure out what was happening only by hooking up a network analyzer.<br> Much to our surprise, our system was routing machines across our WAN links during browsing. After much investigation, we ruled out our network hardware as the source of trouble. That conclusion meant the problem was probably Microsoft-related. <br> At Microsoft’s Web site, finding documentation describing how to deal with the problem was a nightmare. NT requires a Registry fix, Win95 a network setting, and WFW a line added to the system.ini file. We knew that Microsoft’s network performance suffered compared to other networks, but carefully setting up each user’s machine lets you have reasonable performance. However, this setup is a lot of work for your MIS staff. I feel sorry for the administrators who aren’t affected as drastically as we were. They will probably just accept the performance hit as part of life with Microsoft networking. My thanks for a timely and very important article.<br> --Paul Hunter
Paul Hunter August 13, 1999
George Spalding’s August article, “Too Many Servers Spoil Network Performance,” was very informative. Can you describe how a WINS server affects browsing? Will workstations contact the WINS server rather than a browser?<br> --Tom Rossi<br><br>
<i>Workstations configured as WINS clients and TCP/IP “h” nodes will first contact the WINS Server to resolve a NetBIOS name; if unsuccessful, they will then broadcast a request for a backup browser. Once WINS is in place and correctly configured with load balancing, replication partners, and so forth, the only browser traffic is registration on bootup and every 12 minutes thereafter for every machine and every protocol. NT still needs the browser for applications such as Server Manager. <br> --George Spalding</i>
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My company is headquartered in St. Louis, Missouri. We implemented a new NT server-based corporatewide domain shortly after NT 4.0 came out, and we have WAN links to Florida and to Alvarez, Mexico. Users at both locations are members of the corporate domain, so clients at both remote locations began winning master browser elections.<br>
Our link to Florida is 256KB. When machines in Florida served as domain master browser, browsing the Network Neighborhood or opening File Manager or Explorer began taking several minutes to complete. In Mexico, our link is just 56KB, and when a machine there became the domain master browser, the problem was much worse.<br>
Machines in St. Louis that were attempting to browse were being routed to a machine in Mexico. Once we had enough machines trying to browse, the pipe to Mexico jammed. At that point, anyone attempting to browse would lock up, regardless of OS. Naturally, we had users rebooting all over the network. We were able to figure out what was happening only by hooking up a network analyzer.<br>
Much to our surprise, our system was routing machines across our WAN links during browsing. After much investigation, we ruled out our network hardware as the source of trouble. That conclusion meant the problem was probably Microsoft-related. <br>
At Microsoft’s Web site, finding documentation describing how to deal with the problem was a nightmare. NT requires a Registry fix, Win95 a network setting, and WFW a line added to the system.ini file. We knew that Microsoft’s network performance suffered compared to other networks, but carefully setting up each user’s machine lets you have reasonable performance. However, this setup is a lot of work for your MIS staff. I feel sorry for the administrators who aren’t affected as drastically as we were. They will probably just accept the performance hit as part of life with Microsoft networking. My thanks for a timely and very important article.<br>
--Paul Hunter
Paul Hunter August 13, 1999