Remote access to my Plex server

[b_abbott]

I have a plex server running on my Telus Fiber.  Recently some remote family members have lost access while others have no problem at all.  The two remote users are both on Telus fiber with T3500M modems.  They can gain access via the cellular network but not the Telus internet connection.  Niether WiFi nor wired connection will work.  I have tested the connections from their homes using my laptop which I know the software works.  Both modems have been rebooted.

Any ideas what could have changed?

Thank you in advance

Retired Telus employee.

[FuzzyLogic]

This may be of use:

Troubleshooting Remote Access | Plex Support

[b_abbott]

Thank you for your email. I have done everything in the Plex support section with the same results.

[CouchElephant]

You need to forward the port that Plex uses to listen to connections, from your Plex server device to your router. There's a port forwarding setting in the router web portal

[b_abbott]

Thank you but have already done that. Also checked to my sure the port was open. The 2 clients that are having a problem can connect using their cellular but not through the internet on any device. Both are on Telus Fiber.

[FuzzyLogic · Accepted solution]

Possibly a DNS issue:

DNS Rebinding

Some routers or modems have a feature known as “DNS rebinding protection”, some implementations of which can prevent an app from being able to connect to a Plex Media Server securely on the local network. For most users, this won’t be an issue, but some users of higher-end routers (or those provided by some ISPs) may run into problems.

Similarly, some DNS providers (including some ISPs) may have this feature.

DNS rebinding protection is meant as a security feature, to protect insecurely-designed devices on the local network against attacks. It provides no benefit for devices that are designed and configured correctly.

ISP Settings

In some cases, your ISP itself may provide rebinding protection when using their DNS services. In this case, you can switch to using a different DNS service. Depending on your personal setup, you may need to update either your router’s configuration, the configuration on your computer(s), or both.

There are many free and easy-to-use alternative DNS services. Some of the more popular:

• https://1.1.1.1/ (a “privacy-first” DNS responder)
• Google Public DNS
• OpenDNS
• Quad9

Source How to Use Secure Server Connections | Plex Support

I personally use Quad9 for my DNS services.