A user is unable to reach Google.com by typing the URL in the web browser but is able to reach it by typing in 172.217.3.110. What is the cause?

The issue described suggests a problem with DNS (Domain Name System) resolution. Here's a breakdown of the situation:

Step 1: Define the Problem

The user can access Google.com using its IP address but not by typing the URL. This indicates a problem with translating the domain name into an IP address.

Step 2: Break Down the Problem

1. DNS Resolution Issue: The DNS server is not translating the domain name (Google.com) into its corresponding IP address.
2. Local DNS Cache: There might be an issue with the local DNS cache on the user's device.
3. Network DNS Settings: The DNS settings on the user's network might be incorrect or misconfigured.

Step 3: Apply Relevant Concepts

• DNS Functionality: DNS servers are responsible for resolving domain names to IP addresses. If this process fails, users cannot access websites using domain names.
• Troubleshooting Steps:
  • Clear the local DNS cache using the command ipconfig /flushdns on Windows or sudo dscacheutil -flushcache on macOS.
  • Check the DNS settings on the device and ensure they are set to a reliable DNS server, such as Google's DNS (8.8.8.8).

Step 4: Analysis, Verify and Summarize

• Verify DNS Configuration: Ensure that the DNS settings are correctly configured on the user's device and network.
• Test DNS Resolution: Use tools like nslookup or ping to test if the domain name can be resolved to an IP address.

Final Answer

The cause of the issue is likely a DNS resolution problem. The user should check their DNS settings and clear the DNS cache to resolve the issue.