A structured lesson workspace with readable content, hands-on examples, and a clean path to completion.
You type google.com and press Enter. In under a second: your laptop asks 'what is google's number?', gets an IP, packs your request, your router forwards it across the ISP, Google replies. Four helpers did the work: DNS, IP, MAC, TCP/ports. Let's meet them.
Remember this one line for the whole CCNA: IP is end-to-end (stays same from you to Google, unless home NAT), MAC is hop-by-hop (rewritten at every router). Every routing bug later assumes you know that.
First command asks DNS for the number. Second proves IP reachability to that number. If nslookup fails but ping 8.8.8.8 works, it's a DNS problem, not internet down — very common ticket.
Field note: 'Internet is down' is wrong 60% of the time. Test DNS first, then IP. If google.com fails but 8.8.8.8 pings, fix DNS, don't reboot the router.
You now know the 4 helpers behind every click. Next: touch the physical stuff — cables, ports and lights.
Finish the lesson once you have worked through the material. This awards ★ 25 XP.