Solved plex app vanished from firewall built-in app list

[butala]

Hello everyone,

Who know I'm luckier here than posts in Synology Forum and Plex Reddit.

I had a couple times in the last 2 years issues with an outside connection within plex as ilustrated below.

I always could get rid of this kind of error by restarting DSM.
This time it was diferent, though. So I took a look at the firewall settings and realized that the port 32400 set for plex wasn't enabled. Even worse, the plex application was missing from the list of built-in applications.

Control Panel>Firewall>Edit Rules>LAN 1>Editing a Profile>Select from a list of build-in applications>(missing Plex built-in app with its port 32400).

So I created a custom rule that works also, but this is unusual.

Have anyone ever had such a odd situation where the built-in application vanished from appearing? And how I can get it back?

Thanks in advance

 

[Rusty]

Hello everyone,

Who know I'm luckier here than posts in Synology Forum and Plex Reddit.

I had a couple times in the last 2 years issues with an outside connection within plex as ilustrated below.

I always could get rid of this kind of error by restarting DSM.
This time it was diferent, though. So I took a look at the firewall settings and realized that the port 32400 set for plex wasn't enabled. Even worse, the plex application was missing from the list of built-in applications.

Control Panel>Firewall>Edit Rules>LAN 1>Editing a Profile>Select from a list of build-in applications>(missing Plex built-in app with its port 32400).

So I created a custom rule that works also, but this is unusual.

Have anyone ever had such a odd situation where the built-in application vanished from appearing? And how I can get it back?

Thanks in advance

Personally I never use the built-in list and do all my port forwards by hand, manually. Why it is no longer on the list? No ide of the top of my head, but I think it would be best to focus on the manual port forwards. for decades I have never lost access to any service in my lan that was not a result of something else other then port forward.

 

[fredbert]

To confirm:

You have a manual port forwarding and firewall rule in your Internet router that forwards incoming TCP 32400 to TCP 32400 on the NAS's reserved LAN IP address?

And now you also have a custom DSM firewall rule allowing [whichever source IPs] to access its TCP 32400, which is the port that Plex is listening on.


I've not had this problem but I'd first try clicking 'Retry' in Plex and then restarting Plex, and then rebooting DSM.

 

[butala]

To confirm:

You have a manual port forwarding and firewall rule in your Internet router that forwards incoming TCP 32400 to TCP 32400 on the NAS's reserved LAN IP address?

And now you also have a custom DSM firewall rule allowing [whichever source IPs] to access its TCP 32400, which is the port that Plex is listening on.


I've not had this problem but I'd first try clicking 'Retry' in Plex and then restarting Plex, and then rebooting DSM.

Personally I never use the built-in list and do all my port forwards by hand, manually. Why it is no longer on the list? No ide of the top of my head, but I think it would be best to focus on the manual port forwards. for decades I have never lost access to any service in my lan that was not a result of something else other then port forward.

It would be not so inconvenient doing manually as I also do in my router, if by entering a value for the port we could also tag it in order to identify it. After a lot of ports, we easily get lost with those numbers. In the router it is possible identify each port input.

 

[butala]

To confirm:

You have a manual port forwarding and firewall rule in your Internet router that forwards incoming TCP 32400 to TCP 32400 on the NAS's reserved LAN IP address?

And now you also have a custom DSM firewall rule allowing [whichever source IPs] to access its TCP 32400, which is the port that Plex is listening on.


I've not had this problem but I'd first try clicking 'Retry' in Plex and then restarting Plex, and then rebooting DSM.

Thanks to reply. For the 1st question, yes I do have. And for firewall setting on DSM it is correct also.

I tried all this, retry in plex, restart plex and reboot DSM. But was the first time I restart plex and the plex app disappeared from the list. On the other hand, by just restarting DSM the plex app was always left untouched.

 

[fredbert]

I just had a thought.

In DSM firewall, which interface did you place the rule for Plex? Or rather there is a precedence in firewall rules:

1. All interfaces are used first: if nothing matches (top to bottom) then the specific rules for the interface are used.
2. Specific interface rules (e.g. LAN 1): if still nothing matches then the catch-all rule that is set for each interface will be used:
   • Allow access, or
   • Deny access

If you didn't have a specific rule before (was Plex listed as an application? It's a third-party package) and you inbound interface was set to default to 'Allow access' then Plex would be accessible. If you've tidied up the firewall policy with a Deny access then that would stop Plex direct access.

 

[butala]

I just had a thought.

In DSM firewall, which interface did you place the rule for Plex? Or rather there is a precedence in firewall rules:

1. All interfaces are used first: if nothing matches (top to bottom) then the specific rules for the interface are used.
2. Specific interface rules (e.g. LAN 1): if still nothing matches then the catch-all rule that is set for each interface will be used:
   • Allow access, or
   • Deny access

If you didn't have a specific rule before (was Plex listed as an application? It's a third-party package) and you inbound interface was set to default to 'Allow access' then Plex would be accessible. If you've tidied up the firewall policy with a Deny access then that would stop Plex direct access.

That's the first time I had difficulties with firewall related to plex access namely port 32400 since its installation of almost 2 years ago. So, because you ask me if plex was listed as an application, because it is a third-party package, got me thinking about and I must admit that I'm not so sure if it was listed as an application anyhow. However, even if plex isn´t listed as an application, there is no reasonable explanation why the port 32400 has vanished from firewall rules on all interfaces. That makes me incredulous. All you have referenced in item 1 and 2 I'm aware of.
But sincerely I wouldn't be able to find the culprit/cause of this event anyway. There is no registry where changes on settings are made we could follow-up. I would suggest to close this thread, it is working anyway.
Thank you for your attention.