Trying to setup dynamic DNS forwarding through my router with HTTPS. Router says port is open, nmap says port is open, but the browser reports "Site can't be reached" and <UNC> "unexpectedly closed the connection." and finally ERR_CONNECTION_CLOSED. Error message in ISY reports "System -170001 [TCP-Conn] -6/-140002, Portal-Dispatch".

This error does not appear in the ISY error list at "ISY-99i/ISY-26 INSTEON:Errors And Error Messages".

Any clues? I have tried adding the WEB/xxxx paths after the UNC without effect.

Thanks!

Who is your ISP? A new technology on the ISP scene is CGNAT, where they put a NAT router between your router and the internet, which renders local firewall holes ineffective. They're doing for a different reason, but the effect is the same.

CGNAT is the beginning of the end of opening firewall ports to access your local devices.