Define the failing path
Start with the exact symptom and identify the dependency that must work for the operation to succeed. Capture the server name, source system and the exact error before making changes.
IP configuration
Test the relevant dependency directly. Use a focused connectivity or configuration check instead of relying on a generic ping or a single management tool.
NSGs
Review the Windows, virtualization or cloud configuration that controls the failing operation. Compare the expected configuration with the actual state.
Routes
Check security controls such as Windows Firewall, network security rules, authentication and permissions. Confirm the rule applies to the correct network profile, interface or identity.
DNS
Validate the result after each change. Record what changed and whether the original symptom is resolved before moving to the next step.
Guest OS
Turn the final checks into a repeatable runbook or scheduled report so the same issue can be diagnosed faster next time.
Useful commands
Run these checks from an elevated PowerShell session where appropriate. Replace example names with your environment.
Azure CLI checks
az vm show -g RG01 -n VM01 --show-details
az network nic show-effective-nsg -g RG01 -n VM01NICQuick troubleshooting path
Use this sequence to isolate the failing dependency before changing production configuration.
What good troubleshooting looks like
Good infrastructure troubleshooting is evidence-driven. Capture the original state, test the dependency that can prove or disprove your hypothesis, make the smallest safe change and repeat the original test.
Symptom → hypothesis → direct test → result → controlled change → validation → documentation
Frequently asked questions
What should I check first?
Start with the exact symptom and validate the dependency closest to the failure, such as DNS, a port, a service, storage or an authentication path.
Should I change production configuration immediately?
No. Capture the current state first, test the suspected dependency and make one controlled change at a time.
How should I document the fix?
Record the symptom, commands used, result, configuration change and validation result so the procedure can be repeated.
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