How does DNS resolution work, and what steps would you take to troubleshoot a situation where a user can ping an IP address but cannot access a website by its domain name?

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DNS, or Domain Name System, is the service that translates human-readable domain names like google.com into the numerical IP addresses that computers use to communicate. When a user types a URL into their browser, the system needs to resolve that name to an IP address before it can establish a connection.

The resolution process starts with the client checking its local DNS cache to see if it already has a recent record for that domain. If not, it queries the configured DNS server, which is usually provided by DHCP or set manually. That DNS server may have the answer cached from a previous lookup. If it does not, it begins a process called recursive resolution, where it queries root name servers, then top-level domain servers, and finally the authoritative name server for that specific domain. Once the IP address is found, it is returned to the client and cached for future use.

When a user can ping an IP address successfully but cannot reach a website by name, the issue is almost certainly DNS-related rather than a general connectivity problem. Here is how I would troubleshoot this step by step.

First, I would open a command prompt and run nslookup followed by the domain name. This tells me whether the DNS server is responding and what address it returns. If nslookup times out or returns an error, the DNS server itself may be down or unreachable.

Second, I would check the client's DNS configuration by running ipconfig /all on Windows or cat /etc/resolv.conf on Linux. I want to confirm that the DNS server addresses are correct and match what the organization expects.

Third, I would try flushing the local DNS cache using ipconfig /flushdns on Windows. Sometimes stale or corrupted cache entries cause resolution failures.

Fourth, if the configured DNS server is not responding, I would test with a known public DNS server like 8.8.8.8 by running nslookup google.com 8.8.8.8. If that works, the problem is with the organization's DNS server, not the client.

Fifth, I would check whether the issue affects one specific domain or all domains. If only one domain fails, the problem may be with that domain's DNS records rather than the client's configuration.

This systematic approach quickly isolates whether the issue is on the client side, the DNS server side, or with the domain itself.