Phase 3 — Networking
Networking & Wi-Fi
The chain from ISP to endpoint, and how to find the broken link.
What you will be able to do
- ▸Draw and explain the office network chain from memory
- ▸Isolate 'the internet is down' to a specific layer in minutes
- ▸Use ping, ipconfig, nslookup and tracert with intent
Lessons
The chain: Internet → ONT → Router → Switch → AP (Access Point) → Endpoint
Almost every small office is the same six-link chain. Learn it once and you can walk into any of them.
IP (Internet Protocol) addressing, DHCP (Dynamic Host Configuration Protocol) and DNS (Domain Name System)
Three concepts explain most connectivity tickets: what address do I have, who gave it to me, and can I resolve names?
'The internet isn't working' — isolate it in five minutes
The most common call in small business IT (Information Technology), and the one that most separates professionals from part-timers.
Area check
Pass at 70% to bank the area.
1. A laptop shows IP address 169.254.14.9. What does this mean?
2. You can ping 1.1.1.1 but no website loads. Most likely cause?
3. Complaints come only from the back treatment rooms. Where do you look?
4. What does a managed switch add that an unmanaged one does not?
5. Which command shows where along the path traffic stops?