The Basics of Remote Access Troubleshooting

[tom80H]

When it comes to remote access, there’s a lot of different factors which can impact your setup. Some are under your own control, others not so much.

First off… there’s a dedicated support article on troubleshooting your remote access. I strongly recommend you have a look at that.

Find below some additional remarks on how to troubleshoot your remote access setup.

Review your internet access / remote access configuration

• It’s good practice to review if Plex gets the correct public IP address of the main router in your home network.
• Make sure your router is configured to assign the same static local IP address to your PMS (e.g. IP reservation)
• Plex’ remote access depends on your home network to have a publicly routable IPv4 address. Common problems are environments where your ISP assigns only a private IPv4 address or no IPv4 address at all (some ISPs have started moving their network entirely to IPv6).

UPnP vs. manual port forwarding

Not all routers support manual port forwarding. Though based on experience in the forum, manual port forwarding seems to be more stable/reliable – there’s e.g. less remote access dropouts if the router shifts your UPnP connection to a different port.

Therefore, if possible, try to disable UPnP and establish a manual port forward to your router instead.

General configuration

Wording of those properties will vary depending on your router; some vendors e.g. use External/Internal instead of Public/Private.

Property	Configuration
Protocol	TCP
Public IP	this will be the router’s public IP address (WAN IP); some routers expect it to be entered as a separate property anyway
Public Port	you’re free to pick this value… preferably pick one in the range of 20000 to 50000 to avoid accidental collisions
Private IP	<local IP of your PMS>
Private Port	32400

http://portforward.com/ has a wide range of manuals on how to configure a manual port forward for specific routers.

What’s wrong?

If Plex’ remote access still isn’t working after enabling your manual port forward, it’s time to dig deeper. Test if you can see the router’s public IP and the specified public TCP port. You can do this using a service like canyouseeme.org.
This is usually another opportunity to verify if the public IP they see is the same seen by Plex and your router itself.

• If you can see your router, this implies the issue is inside your home network (between your router and the Plex Media Server, including both endpoints).
• If you cannot see your router, this implies the issue is outside your home network (between “the internet” / your ISP and your router)

(1) Common issues

• Plex remote access settings show that it’s working… then it’ll lose access after a few seconds/minutes
  Best way forward: Assume that your remote access setup isn’t working at all. Plex takes an „optimistic approach“ to displaying the remote access status — it’ll display that everything is working while still testing the status. This usually takes a few seconds… it’s not unheard of to take 20-30 seconds or in exceptions up to 1-2 minutes.

• Despite all the effort… reality shows that errors happen all the time (stupid typos, mismatching configurations…)
  Best way forward: Double-check the manual port forward configuration of your router

• Anything VPN
  Best way forward: The easiest way forward should be creating an exception for Plex to bypass the VPN. I take it that’s not a satisfying solution for some… which will leave you with lots of individual troubleshooting beyond this post/thread.
  There’s e.g. a number of known “VPN helper tools” which will write IP addresses to the server’s hosts file that can give Plex some hiccups.

(2) Common “inside your home network” issues

• Hierarchical home network configuration and segmentation getting in the way; some active network components create their own subnet inside your home network.
  Best way forward:

  • Accidental segmentation: Review the configuration of your active network components (e.g. WLAN access points, other routers inside your home network). If possible, set them into “bridge mode” by disabling their built-in DHCP server. This way they should get their IP addresses from the main router and no longer form an obstacle for your remote access.
  • On purpose: If you segmented your home network on purpose, review those configurations and make sure to forward the communication through ALL of those network (from the main router down to the subnet hosting your PMS).
    This can also apply to containerized PMS setups which don’t use bridge network mode!

• Security restrictions implied by firewalls or security tools
  Best way forward: Temporarily disable such components one-by-one to figure out which of them is impacting the Plex remote access communication. If needed, adjust their configuration to allow

• Windows network profiles getting in the way → if you’re hosting your PMS on a Windows machine which has classified your network as public, this can block it from allowing outside access to the PMS
  Best way forward: Change the network classification to private.
  https://docs.microsoft.com/en-us/answers/questions/73866/how-to-change-network-settings-from-public-to-priv.html

• Bad Plex remote access configuration
  Best way forward: Double-check your configuration matches that of the manual port forward; sometimes it can help to also look into the Plex network settings (e.g. some bad custom access URLs / certificates…).

(3) Common “outside your home network” issues

• ISPs blocking certain ports…
  Best way forward: You can attempt changing the public TCP port of your port forward… until you find one that works. Sometimes it’s enough to use a port different from 32400, sometimes you have to go a long way.

• ISPs blocking certain traffic (some more advanced filtering)
  Best way forward: Talk to your ISP

You don’t need a “static public IPv4” address for Plex remote access to work. That won’t stop many ISPs from offering such an option… usually for a steep price.

What else could be wrong?

After you’ve verified the above and your remote access issues persist, you might want to take a look at your server logs. Specifically search for…

• Error messages and references of certificate issues (this is usually linked to error code 429). This usually indicates an issue of your server obtaining a new certificate. This usually implies some connectivity issue (e.g. your server failing to resolve the address providing the certificate) or might require a certificate reset by a Plex team member.

• References to Rebind errors. Those can be fixed by allowing a rebind protection for plex.direct (see: “Why isn’t it working? (DNS rebinding)” in the support article on How to Use Secure Server Connections); sometimes, changing DNS could also resolve those (e.g. switching to Google DNS or Cloudflare public DNS).

[premikkoci]

(4) Plex still ignores ipv6 remote access in 2022

[tom80H]

I suppose that’s covered by Review your internet access / remote access configuration and the statement that you need a publicly routable IPv4 address.

On the other hand, the assumption isn’t entirely true:
I have an IPv6 only setup by my ISP and can access my server from outside my home network (based on an IPv6 port forward). Even if Plex Web complains that remote access isn’t available.
However… IIRC this currently only works with the Plex clients for iOS and Apple TV.

[Lifeldga]

So at the end of this nice instructions/guide how to configure remote access you mentioned:

"

• ISPs blocking certain ports…
  Best way forward: You can attempt changing the public TCP port of your port forward… until you find one that works. Sometimes it’s enough to use a port different from 32400, sometimes you have to go a long way.
  "

that is painfull process to go through if you are lucky Do know there are sites like port checker that looks all open ports of you router (if you provide you router IP or ISP number). this will help to make it easier and not to have to go a long way before open unused port is found.

I use the following online port checker tool —> Open Port Check Tool - Test Port Forwarding on Your Router

[tom80H]

@Lifeldga

Do know there are sites like port checker that looks all open ports of you router (if you provide you router IP or ISP number).

There’s lots of services that’ll let you scan individual ports (and probably also port ranges). I suppose many routers will not respond if they recognize that scan to be some kind of attack.

That being said… scanning your own router for restricted ports isn’t the same as checking which ports might be blocked by your ISP. There’s obviously a correlation but the blocking might just as well happen on your router (e.g. if it has some kind of protection against brute force Scans or simply because that particular port isn’t actually forwarded).
Asking the ISP might be much more straightforward.

[davidgiga1993]

Still the case in 2023.. More and more ISPs only provide IPv6 in my Country and the public IPv4 is shared for many customers, thus public access only works via IPv6. I can access my plex server using my own domain using ipv6, however using the plex apps it still tunnels through the slow plex proxy instead of directly going to the server. Any way to fix this?

[tom80H]

Which apps exactly are that for you? IIRC the server itself will handle IPv6 connections (except the remote access status indicator might be thrown off). But I remember having some properly working remote connections from iOS/tvOS and Plex Web in my old apartment (with an IPv6-only ISP).

If I read the release announcements correctly, the regular desktop client (Plex for Mac/Windows/Linux) might also work. I don’t have confirmation for the other clients but I could imagine the Plex clients will in some cases depend on how their host OS (e.g. the smart tv / gaming console…) handle such a network setup (or what APIs they allow/offer to do so).
Some users apparently got things to work by adding their IPv6 address as a custom access URL (server network settings).