One of the most useful questions in network troubleshooting is also one of the simplest:
Does it fail from another machine too?
If a website will not load on my laptop, trying it from another computer can immediately change the investigation.
If it works there, the service probably is not down. Something about my machine, DNS configuration, VPN, firewall, route, or network path is different.
If it fails there too, the problem may be farther upstream.






