Five Ways to Troubleshoot Microsoft Server 2003 on a Network

Windows Server 2003 without a network is like a bicycle without wheels or chips without salsa.

Because Windows Server 2003 and networking go together like gangbusters, your gang (of users) may try to bust you when the network stops working. Try as you may to avoid it, it does happen from time to time. When the network goes on vacation, but you're still in the office, read over these tips and tricks to get things shipshape again.

Never overlook the obvious
The number one cause for failed networks is — you guessed it — loose connections. Always check a server's network interface cards (NICs) to make sure that the cables are still plugged in or otherwise attached. Also, be sure to check all hubs, the routers, the Integrated Services Digital Network (ISDN) box, the modem, and anywhere else the cables go (such as the client machines).

Networking experts often talk about a troubleshooting pyramid that follows the progression of network capabilities up from the hardware and cables, through the protocol stack, to the applications that request network services. In this analogy, the base of the pyramid is far bigger than the top. This pyramid illustrates that problems are most likely to occur at the physical level of networking. Why? Because that's where the cables and connections are. Go ahead — check them again.

Ensure Windows 2003 routing
Windows 2003 happily enables you to insert two or more NICs or other devices that can carry network traffic — such as modems, ISDN boxes, or even Channel Service Unit/Data Service Units (CSU/DSUs) for high-speed digital networking. Doubling up on NICs (or the other network traffic devices listed) allows Windows 2003 to move traffic from one connection to another. This capability, known as routing, enables Windows 2003 to connect separate pieces of a network.

The most exposed and important part of many networks is the link that ties a local network to the Internet (or at least, to your local Internet Service Provider). If Windows 2003 fills that role on your network, be prepared to perform regular troubleshooting rituals to keep this all-important link to the outside world running.

If you can, you should isolate this function on a separate computer. This is a good idea for two reasons:

Adding the burden of routing traffic and managing an Internet interface requires additional software and services that can tax a (possibly overburdened) Windows Server 2003.
You should limit the impact of system failure to as few services as possible. Chances are that your users will be less unhappy if they lose only Internet access or only access to shared files and applications, rather than losing both at the same time.
If you do use a Windows Server 2003 system as a router, especially if an Internet link is involved, think about installing firewall software, such as Microsoft's Proxy Server or Ositis Software's WinProxy, on that machine. A firewall protects your network from interlopers and allows you to monitor and filter incoming (and outgoing) content and information.


Install a fast server NIC
On a Windows 2003 Server, performance is the name of the game. In networking, because network traffic tends to congregate at the server, spending extra bucks on a fast, powerful NIC makes sense. At a bare minimum, you want a Peripheral Component Interconnect (PCI)-based NIC because it offers the best bus connection to the rest of the system. Other hardware enhancements worth purchasing for Windows Server 2003 NICs include the following:

Direct Memory Access (DMA): Enables the NIC to transfer data directly from its on-board memory to the computer's memory without requiring the CPU to mediate.
Shared adapter memory: Enables a NIC's on-board RAM to map into the computer's RAM. When the computer thinks it's writing to its own RAM, it's writing straight to the NIC; and when it thinks it's reading from its own RAM, it's reading straight from the NIC. Shared system memory works the same way, except the NIC reads from and writes to the computer's RAM instead of its own on-board RAM. Extra memory for NICs is almost as good as more RAM on Windows 2003 PCs!
Bus mastering: Lets the NIC manage the computer's bus to coordinate data transfers to and from the computer's memory. Bus mastering enables the CPU to concentrate on other activities and can improve performance by 20 to 70 percent. This is the most worthwhile of all the enhancements mentioned here.
On-board coprocessor: Puts an additional CPU on a NIC and allows the NIC to process data that the CPU would otherwise have to handle. Many NICs today use such processors to speed operations.
The idea is to put the processing power and speed where it does the most good: on the NIC that all the users must interact with to obtain data from (or move packets through) a server. In fact, if you have the money, you may want to investigate building backbones that use alternate or high-speed connections, such as FireWire (which is defined by IEEE 1394), Fibre Channel, Asynchronous Transfer Mode (ATM), or Gigabit Ethernet.

Know when to divide and when to conquer
When traffic reaches high levels on a network segment, traffic jams occur just like they do at rush hour on the highway. When this happens, you need to improve the existing roads (switch to a faster network technology) or add more roads (break up the existing network and put one subset of users on one new piece, another subset on another piece, and so on).

How can you figure out when traffic is starting to choke your network? Easy! Windows Server 2003 includes a service called Network Monitor (affectionately called NetMon) that you can install on your server to monitor the traffic moving into and out of your server (and on the cable segment or segments to which that server is attached).

NetMon doesn't install on Windows Server 2003 by default, but it's easy to add. Choose Start --> Control Panel --> Add or Remove Programs --> Add/Remove Windows Components --> Management and Monitoring Tools. Then click the Details button, select the Network Monitor Tools check box, and click OK. After you follow the instructions from there, NetMon shows up in the Administrative Tools folder (Start --> Administrative Tools --> Network Monitor).

Get to know NetMon, and you get to know your network much better!


Watch network trouble spots
The best way to shoot network trouble and other types of system problems is to stop them before they ever happen. The only way to prevent problems and keep your network running is to study your network environment closely and carefully and figure out where its weak points are. Do this before your network demonstrates its weaknesses to the world at large by breaking.

If you keep an eye on potential trouble spots and perform regular maintenance and upkeep activities (such as scheduled backups, file system cleanups, upgrades, service packs, and hotfixes), you can prevent problems. Remember that preventing problems isn't just less work, it's also the cause of far less unwanted notoriety than fixing things after they break. Don't feel compelled to learn this the hard way!