Revealed! Secrets behind IT magic tricks

When you're good, you can troubleshoot anything -- most of the time. Here are a few riddles and their solutions

Some IT folks have the magic touch when it comes to both consumer and enterprise computing gear. The same digits that might circumvent a bad situation by feverishly freehanding code into a switch to account for an unforeseen failure can also deftly cure an ailing smartphone.

This ability isn't without its drawbacks. For one thing, it can inspire jealousy and frustration when a seemingly insurmountable problem is spirited away in just a few seconds by someone with the touch. I suppose beating your head against a door for a few days only to have someone pull the handle instead could do that to someone.

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But as any magician knows, these tricks aren't magic at all -- you just need inside knowledge and a little practice. For those of you who aspire to wizard status, here's a couple real-world encounters of ghosts in the system.

Home router chaos
This situation usually occurs when someone is at home, connecting via a cable or DSL router. They've had a power outage or brief hiccup and possibly even an inadvertent connection to a neighbor's access point. After much gnashing of teeth, the router is power cycled, but that appears to have worsened the problem. After a period of utter dismay and forsaking all gods, the user finally reboots or power cycles everything in the area, and it all starts working again.

What's actually happened here is a series of DHCP address collisions. The router in use is of sufficiently poor design that it does not maintain DHCP lease tables across reboots, and it extends that deficiency with the lack of ICMP checking before handing out new addresses. Thus, when it powers back up, it dispenses addresses to anything that asks, regardless of whether that IP is already in use. Chaos ensues; some OSes figure out there's a duplicate IP, so they request another. This then breaks a running app and poof -- the TiVo in the back room won't connect to anything, and the wife or husband sitting on the couch is thrown off the network. Anarchy!

The remedy for this is fairly simple: Buy a better router. It's not terribly hard to do.

Proximity-aware printers that hate Jim from engineering
The massive multifunction document center printer/copier in the finance department absolutely hates Jim from engineering. Every damn time Jim shows up for budget meetings or whatnot, the printer throws a fit, spitting out half-documents if it works at all and sending network scans and faxes into the ether, never to be seen again. It took many months for this phenomenon to be fully realized and several more for it to magically disappear on its own, like a poltergeist. To this day, half the finance group wants to ban Jim from the area, but they can't justify it to the higher-ups. What would they say? The big printer hates him?

This case is a little peculiar. It involves Marcy from finance, though she doesn't know it. You see, Jim went over to Marcy's house on a Saturday to fix her wireless network. (This is not an euphemism; Jim's just a nice guy.) While there, he configured it as a simple wireless bridge since her DSL router doesn't have wireless, but is providing DHCP and so forth. During the course of troubleshooting the network, Jim joined the wireless network with his smartphone and hard-coded an IP address into the phone because there was a problem with the DHCP that he later fixed. Months later, Marcy's DSL service was upgraded, and the upgraded router came with Wi-Fi. The installer pointed this out to Marcy, and she opted to use that, freeing up her separate access point.

Now armed with the extra access point, she thinks about how great it would be to be able to add wireless to her office so that she wouldn't have to plug and unplug all those cables from her laptop. She brings in the access point and plugs it into the wall. All is well until Jim comes over and his phone automatically joins Marcy's network -- and is hard-coded to the IP address of the printer.

The moment of borrowed clarity
I know that every IT pro reading this has run into this sort of problem: You've been working on a project or task that's absurdly simple in theory, but just isn't clicking. You've gone over it a few dozen times without thinking, yet in this case, the rules don't seem to apply -- the known becomes the unknown once more.

After toiling on a problem like this for a while, the frustration level grows exponentially. You've tackled this very duty a dozen times before and it's always worked. You aren't trying to venture into the unknown; you're following a familiar trail that suddenly has a mountain in the middle. This is invariably the time when a colleague comes over to discuss another matter, and during the course of that conversation, you mention your problem, at which point he blithely asks a single, simple question that provides the answer. It's like every episode of "House" ever produced.

But that doesn't make it less annoying. The fact that you somehow forgot to HUP the process or that your brain decided a certain syntax has always been one way and not the other or that you inexplicably omitted the functional statement in a route map is a very human occurrence. But hey, we're the ones with the Midas touch, right? This shouldn't happen to us. We understand the magic!

Not always. Sometimes we find ourselves threatening our laptop with an early demise because the magic has abandoned us, if only for a little while.

This story, "Revealed! Secrets behind IT magic tricks," was originally published at Read more of Paul Venezia's The Deep End blog at For the latest business technology news, follow on Twitter.

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