Probe mode
Direct port forwarding, public DDNS and reverse-proxy endpoints should expose a reachable public path. Connection Vitals can verify the TCP connection.
Live connection diagnosis
Remote Access Test
Find whether your problem is the local service, public TCP path, router forwarding, upstream NAT or simply the wrong test for a relay connection.
Remote access diagnostic
Choose the connection method first. Direct paths can be externally probed; relay/overlay methods move into guidance mode.
Detected public IPChecking…
IP version—
Network—
The public IP shown here is detected from this browser request. External probes are restricted to that same public IP.
Two verdict types, because the network paths are different
Guidance mode
Tailscale, vendor relays and overlays deliberately avoid a public inbound port. A failed public port check would be meaningless, so the tool explains the correct verification path instead.
Choose the path you are actually troubleshooting
The right test depends on whether the service is directly exposed, product-mediated or reached through an overlay.
Generic home server
Test one intentionally exposed TCP service, then use WAN/public-IP evidence if it fails.
Windows Remote Desktop
Check the RDP TCP endpoint only if you deliberately expose it; otherwise prefer an overlay/VPN path.
Plex
Separate Plex Direct from Relay before treating a failed public port as the problem.
Jellyfin
Test the actual HTTP(S) or reverse-proxy TCP port used for remote access.
Tailscale
Troubleshoot the overlay path without requiring a public inbound port.
NAS
Choose direct, reverse-proxy, vendor-mediated or overlay access before testing.
If you still do not know where it breaks
The remote-access troubleshooting guide starts with local service availability, then separates direct public endpoints from relay and overlay paths.