If websites fail by name but a public IP address still responds, DNS is the likely layer. Confirm it before changing resolvers.
What DNS does
DNS translates names such as a website address into the numeric addresses computers use. When it fails, the connection can look healthy while browsers report that a server cannot be found.
How to confirm DNS is the problem
Ping a public IP address. If it replies but pinging a website name fails, name resolution is the likely failure. You can also use nslookup with a domain name; timeouts or server-failure responses point to the configured resolver.
- IP address reachable, names fail → DNS.
- Both fail → connectivity problem, not just DNS.
- Only one site fails → that site or its record, not your resolver.
Safe fixes, in order
Start with the least invasive actions and retest after each one.
- Restart the router and the PC.
- Clear the Windows resolver cache with ipconfig /flushdns.
- Try another resolver on the adapter, then remove it if it makes no difference.
- Disable VPN or filtering software briefly to see whether it intercepts DNS.
- Use a network reset only if the above does not help and the network stack looks damaged.
Router versus PC
If several devices have the same DNS trouble, the router or provider resolver is the common factor. Changing the DNS server on the router fixes it for every device, while changing it on the PC fixes only that PC.
Frequently asked questions
Is changing my DNS server safe?
Yes, it is reversible. Choose a resolver you trust, test the result, and set the adapter back to automatic if it does not help.
What does ipconfig /flushdns do?
It clears the local DNS cache so Windows asks a resolver again instead of reusing old answers. It does not change your settings.
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