[Zero Two]

Most networking problems follow the same diagnostic pattern. Work through this before posting - it'll either solve your problem or give you information that makes it much easier to help you.

Step 1: Define the problem precisely

• What exactly fails? Can't load any website? Specific site? Slow speeds? Intermittent drops?
  
• What works? (If some things work, that narrows it down enormously)
  
• When did it start? What changed?
  
• Is it one device or all devices?
  

Step 2: Isolate the layer

Code:

# Can you reach your router?
ping 192.168.1.1   # or whatever your gateway is

# Can you reach external IPs? (tests routing, not DNS)
ping 1.1.1.1

# Can you resolve DNS?
nslookup google.com

# Is a specific site down or just you?
curl -I https://example.com

What the results mean:

• Can't reach router: local network issue (cable, WiFi, switch)
  
• Can reach router, can't reach 1.1.1.1: ISP routing issue or router config
  
• Can reach IPs but not domains: DNS issue
  
• Can reach IPs and resolve DNS but browser fails: browser/proxy/certificate issue
  

Step 3: Check the obvious

• Restart the device (not the router - the device first)
  
• Check cables are seated
  
• Check if a VPN or proxy is active
  
• Disable firewall temporarily to test
  
• Try a different DNS server (1.1.1.1 or 8.8.8.8)
  

Step 4: If posting for help, include:

• OS and version
  
• Connection type (wired/WiFi)
  
• Output of the ping/nslookup tests above
  
• Any error messages verbatim