CompTIA A+ Essentials in 3 Minutes

Transcript

CompTIA A+ is often the first certification for people starting in IT support. It covers a lot of ground, but a handful of ideas come up again and again, both on the exam and on the job. Let me give you four of them.

First, the troubleshooting methodology, in order. One, identify the problem. Two, establish a theory of probable cause. Three, test the theory to determine the cause. Four, establish a plan of action to resolve the problem and implement the solution. Five, verify full system functionality and, if applicable, implement preventive measures. Six, document your findings, actions, and outcomes. Exam questions love to ask what comes next, so learn the order. Notice that documentation comes last, and that you test your theory before you change anything.

Second, common port numbers. Port twenty two is SSH, for secure remote command line access. Port twenty five is SMTP, for sending email. Port fifty three is DNS, which turns names into IP addresses. Port eighty is HTTP, plain web traffic, and port four four three is HTTPS, encrypted web traffic. Port three three eight nine is RDP, the Remote Desktop Protocol for Windows. A trick to remember the web pair: the S in HTTPS means secure, and it uses the bigger number.

Third, RAM versus storage. RAM is fast, temporary working memory. It is volatile, so its contents are lost when the power goes off. Storage, like a solid state drive or a hard drive, is where files live permanently. If a computer slows down when many programs are open, more RAM often helps. If the drive is full, more storage helps. Solid state drives are much faster than spinning hard drives because they have no moving parts.

Fourth, basic networking. An IP address is a logical address that can change depending on the network you join. A MAC address is a physical address assigned to the network interface by the manufacturer. DHCP is the service that hands out IP addresses automatically. If a Windows computer cannot reach a DHCP server, it often gives itself an address starting with one six nine point two five four. That is a strong clue that DHCP failed.

Here is a worked example. A user cannot load any websites. You identify the problem, then check their IP address and see one six nine point two five four. Your theory is that DHCP failed. You test it, fix the connection, verify browsing works, and document it.

Recap: learn the six troubleshooting steps in order, memorize the key ports, know that RAM is volatile, and know IP from MAC.