Our ping checker uses TCP connection testing on ports 80 and 443 rather than ICMP, which is often blocked by firewalls. TCP latency under 200ms is good for web servers. If port 80 is closed but 443 is open, the server redirects HTTP to HTTPS as expected. Both ports closed despite DNS resolution suggests the server uses a CDN proxy or non-standard port. Use this for quick external reachability checks.