Overview #
If your computer says “Connected, no internet” or pages won’t load even though Wi-Fi or Ethernet appears active, the problem is often software-level network configuration, not your router.
This guide helps you systematically diagnose DNS failures, misassigned IP addresses, and network stack corruption on both Windows and macOS — using built-in tools only.
What you’ll learn
- How to verify network connectivity and adapter status
- How to fix DNS and IP assignment issues
- How to reset the network stack and renew connections
- How to confirm your system can reach outside servers
Estimated time: 15–30 minutes
Skill level: Intermediate
Terms and Definitions #
| Term | Meaning |
|---|---|
| DNS (Domain Name System) | Translates website names (like google.com) into IP addresses |
| IP Configuration | The local address, gateway, and subnet used by your device |
| DHCP | Protocol that assigns IPs automatically on your network |
| Network Stack | Software layers that handle all networking (TCP/IP, DNS, Winsock) |
| Ping Test | A diagnostic check to verify that data packets reach a destination |
Steps #
Step 1 — Verify Network Connection and Adapter Status #
Windows PowerShell
Get-NetAdapter | Select Name, Status, LinkSpeed
If the adapter shows Status = Disconnected or Disabled, re-enable it:
Enable-NetAdapter -Name "Wi-Fi" -Confirm:$false
Then check your IP address:
ipconfig
If you see an address like 169.254.x.x, it means DHCP failed — your computer isn’t receiving an IP.
macOS Terminal
ifconfig en0
(Replace en0 with en1 if using Wi-Fi.)
If no valid IP appears, renew DHCP:
sudo ipconfig set en0 DHCP
Step 2 — Run a Basic Connectivity Test #
Windows
ping 8.8.8.8
If you get replies, your physical connection is working.
If that works but ping google.com fails, your issue is DNS-related.
macOS
ping -c 4 8.8.8.8
ping -c 4 google.com
If IP works but names don’t, DNS resolution is the culprit.
Step 3 — Clear and Reset DNS Cache #
Windows
ipconfig /flushdns
Then restart the DNS client service:
net stop dnscache
net start dnscache
macOS
sudo dscacheutil -flushcache
sudo killall -HUP mDNSResponder
This clears outdated DNS lookups.
Step 4 — Reset IP Configuration and Winsock (Windows Only) #
Sometimes your IP or TCP stack gets corrupted by VPNs or power loss.
netsh int ip reset
netsh winsock reset
Reboot afterward.
To release and renew your IP:
ipconfig /release
ipconfig /renew
Step 5 — Assign a Public DNS Manually #
If DNS lookups still fail, set your system to use Google or Cloudflare’s resolvers.
Windows PowerShell
Set-DnsClientServerAddress -InterfaceAlias "Wi-Fi" -ServerAddresses ("8.8.8.8","8.8.4.4")
macOS
sudo networksetup -setdnsservers Wi-Fi 8.8.8.8 1.1.1.1
To restore automatic DNS later:
sudo networksetup -setdnsservers Wi-Fi empty
Step 6 — Reset Network Stack or Location Profile #
Windows
To clear all stored network configurations:
netsh advfirewall reset
netsh interface ip delete arpcache
Then restart the Network Location Awareness service:
Restart-Service nlasvc
macOS
Reset the network location profile:
- Open System Settings → Network.
- Click the “…” → Duplicate Location, switch to the new one, and apply.
- Or use Terminal:
sudo rm /Library/Preferences/SystemConfiguration/NetworkInterfaces.plist sudo rm /Library/Preferences/SystemConfiguration/preferences.plist sudo reboot
Step 7 — Check Router or Firewall Conflicts #
- Restart your router and modem.
- Temporarily disable any third-party firewall or VPN software.
- If you use a corporate VPN, disconnect and test local browsing — VPNs often override DNS.
PowerShell firewall check
netsh advfirewall show allprofiles
Step 8 — Test External Connectivity Again #
Windows
Test-NetConnection google.com
If PingSucceeded = True and TcpTestSucceeded = True, internet access is restored.
macOS
curl -I https://www.apple.com
If you see an HTTP 200 or 301 response, connectivity is good.
Verification #
| Check | Command | Expected Result |
|---|---|---|
| Adapter status | Get-NetAdapter / ifconfig | Connected and enabled |
| IP address | ipconfig / ifconfig | Valid local IP (not 169.254.x.x) |
| DNS | ping google.com | Resolves domain correctly |
| External connection | Test-NetConnection / curl | Successful HTTP or ICMP response |
Conclusion #
When your system says “Connected but no internet,” the culprit is almost always DNS failure, cached IP conflicts, or corrupted network stack settings.
By flushing DNS, resetting IP, and verifying adapter configuration, you can usually restore full connectivity within minutes.
If issues persist, test your router or modem with another device — if that fails too, contact your ISP to verify line-level service.
