Cloud and IT fundamentals
Hardware and operating systems, networking, security basics, vendor-neutral cloud concepts and a steady approach to troubleshooting.
- Hardware and operating systems. Processors, memory, storage, drivers and firmware.
- Networking. Addresses, DNS, DHCP, Wi-Fi, ports and routers.
- Security basics. Least privilege, malware, encryption, patching and backups.
- Cloud concepts. Service models, shared responsibility, regions and cost.
- Troubleshooting. Scoping a fault, testing one change at a time, writing it up.
Hardware and operating systems
- Think, hold, keep. The processor does the thinking. Memory (RAM) holds what is open now. Storage keeps your files when the power is off.
- RAM is your desk. More RAM is a bigger desk: more open at once. Storage is the filing cabinet where everything waits.
- Drivers translate. A driver lets the operating system talk to a device such as a printer. Old drivers cause odd faults.
- Firmware needs updates too. Firmware is software built into a device, like a router. Its updates fix bugs and close security holes.
Networking
- DNS is a phone book. Look up a name, get a number. DNS turns testera.org into an IP address that computers can reach.
- An address for every device. An IP address works like a house number, so each packet knows where to go.
- DHCP hands out addresses. Join a Wi-Fi network and DHCP gives your device an address automatically, like a name badge at the door.
- Ports are doors. One address can run many services. Web pages usually use port 443, one numbered door in the same building.
- The router is the gateway. Your router joins your home network to the internet. Every packet going out or coming in passes through it.
Security basics
- Least privilege. Give each person only the access their job needs. Fewer keys means less damage if one is stolen.
- Patch promptly. Most attacks use holes that already have a fix. Installing updates quickly shuts the door.
- Encryption scrambles. Encrypted data is gibberish without the key. Encrypt laptops and phones, and look for https on websites.
- Backups beat ransomware. Ransomware locks your files and demands payment. A recent backup kept separately lets you restore instead.
Cloud concepts
- Someone else's computers. The cloud is computing you rent from a provider's data centres, instead of buying and running the machines yourself.
- IaaS, PaaS, SaaS. IaaS rents you servers. PaaS runs your code for you. SaaS is a finished app, such as webmail.
- The responsibility line. The provider secures the buildings and hardware. You always look after your data and who can reach it.
- Regions and cost. Choose a region near your users that meets your data rules. You pay for what runs, so switch off what doesn't.
Troubleshooting
- Name the problem. Who is affected, since when, and what changed? A clearly described fault is half solved.
- One change at a time. Change one thing, then test. Change three at once and you won't know which one fixed it.
- Simple things first. Check the power, the cable and a restart before the clever theories. Most faults turn out to be simple.
- Write it up. Note the symptom, the cause and the fix. Next time, you or a colleague can fix it in minutes.
Free practice with a starting check, an explanation after every answer and a final check.