Network hardware failures. Internet outages. DDoS attacks. These are the types of disruptions you probably spend your time preparing to handle. But there’s another potential source of trouble that most IT pros think about much less frequently, and which happens far more often: employee offboarding. Whether an employee is leaving to pursue another opportunity or an employee is being terminated, you need to make sure your company’s network and data are secure.

By even casual observation, you’ll likely have noticed that there are several IP address ranges that are special, including: Anybody can use these “private” ranges for anything they like. But there are actually several other special ranges that have other special purposes. In this article, I’ll explain what they are and the purpose they serve. This is the “loopback” range. These are addresses that are assumed to be on the same device that’s sending the packet.

Whether you’re trying to troubleshoot a problem, defend against attacks, or simply optimize your environment, event logs are your best source of information. More than that, not logging or ignoring your logs is like not checking your blindspot when you’re changing lanes—sooner or later you’re going to seriously regret it because the effects will be disastrous.

Subnetting isn’t hard but I often see even experienced network engineers looking for subnet calculators or trying to count in binary on their fingers. So how about a quick primer? To understand subnets, remember what a subnet is and think about the IP address in binary. A subnet is a range of IP addresses. All the devices in the same subnet can communicate directly with one another without going through any routers.

Marketing teams have the 4 Ps (product, price, place, and promotion). Sales teams have ABC (Always Be Closing). As far as frameworks go, there are a lot of great examples out there for how we can effectively do our jobs, create processes, and make decisions. But what about IT teams looking to optimize their services? Do any frameworks exist? One does, it’s called the triple-A framework—and it’s got nothing to do with batteries.