When you network your computers, occasions arise when it helps to have some items handy to assist in getting back up and running quickly. If you can't find a whole closet, shoot for a shelf, a drawer, or at least a sturdy cardboard box. Here's a list of stuff to keep easily available.
Tools
Make sure that you have at least a basic computer toolkit, the kind you can pick up for $15 from just about any office-supply store. Make sure that it includes a Phillips screwdriver. You also should have wire cutters, wire strippers, and cable crimpers that work for your network cable type.
Extra cable
When you buy network cable, never buy exactly the amount you need. In fact, buying at least twice as much cable as you need isn't a bad idea, because that way half the cable is left over in case you need it later - and you will. Something will go wrong, and you'll suspect a cable problem, so you'll need extra cable to replace the bad cable. Or you may add a computer or two to the network and need extra cable.
If your network is glued together with preassembled 25-foot lengths of cable, having at least one 25-foot segment lying around in the closet is a good idea.
Extra connectors
Don't run out of connectors, either. If you use twisted-pair cabling, you'll find that connectors go bad more often than you'd like. Buy the connectors in lots of 25, 50, or 100 at a time so that you have plenty of spares lying around.
If your network still uses Thinnet cable, keep a few spare BNC connectors handy, plus a few T-connectors and a few terminators. Terminators have been known to mysteriously disappear. Rumor has it that they are sucked through some kind of time vortex into the distant future, where they're refabricated and returned to our time in the form of Arnold Schwarzenegger.
Patch cables
If you wired your network the professional way - with wall jacks in each office - keep a few patch cables of various lengths in the closet. That way, you won't have to run to the store every time you need to change a patch cable. And count on it - you will need to replace patch cables from time to time.
Extra network cards
If you always keep a spare network card around, you can rest easy knowing that if one fails, you have an identical replacement card sitting on the shelf, just waiting to be installed - no matter what the weather's like or whether transportation to a computer shop is available.
If you have only two computers on your network, justifying spending the money for a spare network adapter card may be hard. With larger networks, it's easier to justify.
The complete documentation of the network on tablets of stone
After you've spent hours documenting your network (and you do plan to keep detailed documentation, right?), don't hide the documentation under a pile of old magazines behind your desk. Put the documentation in the closet with the other network supplies so that you and everyone else always know where to find it. And keep backup copies of the Word, Excel, Visio, or other documents that make up the network binder in a fireproof safe or at another site.
Also keep the manuals for all the software you use on your network. Likewise the disks. You may need them someday, so keep them with the other network stuff.
