Public DNS/IP does not seem to be working for Windows Server 2025 machine

Question

Public DNS/IP does not seem to be working for Windows Server 2025 machine. I am trying to expose my Apache web server. I selected "Static IP", I entered the "DNS name label" (xxx.centralus.cloudapp.azure.com ). I opened the ports in the security group but the URL xxx.centralus.cloudapp.azure.com doesn't respond I get a "can't reach that page"

Answer 1

Hi Jim,

To troubleshoot this issue, ensure that the virtual machine is running in the Azure portal. Sometimes, VMs may be stopped or deallocated, in such case the public IP or DNS will not respond. Once confirmed, also verify that the public IP address and DNS name label are correctly configured under the VM's network settings. The DNS label should match the expected format and be properly registered.

Also, ensure you confirm the Network Security Group (NSG) associated with the VM has an inbound rule that allows traffic on port 80(HTTP). This rule should allow any source, use TCP protocol and have the action set to "Allow" . Without this rule, external requests will be blocked even before reaching the server.

Log into the WIndows Server VM using RDP and sure that the Windows Defender Firewall allows inbound traffic on port 80. Even if the NSG allows it, Windows internal firewall may still block the connection. Ensure you enable an existing rule for Apache or run a PowerShell command like New-NetFirewallRule to explicitly allow traffic on port 80.

After confirming firewall, check the Apache web server. Make sure Apache is running and listening on the right network interface. In Apache's configuration file (httpd.conf), the Listen directive should be set to 0.0.0.0:80 or simply Listen 80 to allow connections from all interfaces. Test by trying to access http://localhost from within the VM. If it works, the problem likely is in network configuration rather than the Apache setup.

Restart Apache to apply any configuration changes and test the public URL again. Use tools like curl, telnet, or Azure Network Watcher's Connection Troubleshoot feature, to help determine if the port is reachable externally.

To summarize, verify VM is running, DNS and IP settings are correct, both NSG and Windows Firewall allow port 80 and Apache is correctly configured and running. Verifying these layers will help you to easily identify and resolve the connectivity issue.