Hub 2 Universal Plug and Pray and Firewall issues....

[#1]

Hi All,

I have the Plusnet Hub 2 and I run a Plex Server to stream movies and TV shows around the home and over WAN while I'm out and about. The issue I have is that remote keeps dropping out when using both UPnP and the built in NAT, even the Xbox One S's around the home have shown a DNS error every now and again with these items switched on.

I've had a second Hub 2 recently and within minutes the same issue struck up. I've added all the ports both TCP and UDP that Plex and the Xbox's use to the Port Forwarding, but sadly, with Firewall switched on, it just doesn't work (Firewall on Default) but as soon as I switch the Firewall off, hey presto Remote Access is back on the Plex Server, and Xbox's sing.

I run Ubuntu 20.04LTS for Plex etc, and this issue even shows up on a dreaded Windows PC to, so I know it's not a OS issue.

To combat the Firewall being switched off at the moment, I have set up the one built into Linux and opened the ports there, so the Server is protected to some degree. but would love to finally be able to use the NAT instead of just the one on the PC, so the Xbox's are secure also. I'm not a fan of UPnP as it in itself has security issues, and as I see it, should only have been used for internal networking, but somewhere, some bright boffin thought "I know, lets make it available for WAN too!"

So, there is my dilema, and I wonder if anyone is running the same type of system i.e. Plex or Jellyfin or Emby and have either cured the issue, or like me, have had to resort to dancing with the devil? I see my only other option if it comes to it, is a new router of my own, and hope that Universal Plug and Pray works in conjunction with the NAT that way?

Cheers for any advice or input.....

Dave

[#2]

Hi Dave,

This is a very technical query, which I suspect few will understand let alone be able to help answer.

@bobpullen is the business go-to on these kind of questions, but with his expanded remit, he does not lurk here as much as he used to do.

That said, even if it is confirmed that the behaviour is a 'bug' given the maturity of the Hub 2 I would be very surprised if a new firmware is cut.  The most pragmatic solution here for you would be to obtain a router of your own choice, which offers greater flexibility for users who require more functionality than that of a generic ISP supplied device.

[#3]

@mw0dcm - when you talk of switching firewalls on/off, what firewall exactly are you referring to?

I personally run a Plex server in a similar fashion and I've never experienced any problems using a Hub Two. I typically have UPnP disabled and a simple TCP NAT rule to forward traffic to the machine hosting the Plex server (default port 32400).

Can't help but think something else might be at play here, specifically due to the comment about DNS errors on the XBox.

Anything telling in the hub logs?

[#4]

Sorry for the delay in replying, been a crazy time here in the Rhondda Valleys!!

Since switching off the Firewall on the Hub 2 and just leaving UPNP on, and setting the port manually on the Plex Server (something I've never had to do before now!) and adding 12 ports to the list that Plex uses, things have so far been behaving, but without the Firewall switched on on the Router (Disabled) I feel somewhat exposed to the elements if you know what I mean?

The logs on the old Hub 2 and this one with the Firewall Enabled and UPNP too, did show DNS having issues for some reason.  Ubuntu Network congiguration is how it was when I set it up over 18 months ago, and I haven't switched on/enabled UFW.

I'm about to receive from my friend of 40yrs a Orbi RBR50 and 2 satellites, which I intend to replace the Hub 2 with as I know I can just plug the RBR50 straight into the ONT and then add my user and password for Plusnet to connect. I'll be able to monitor the connection much better with both the NAT and UPNP on and see if the issue rears it's ugly head using that router.

The server is connected via GigE CAT5 and then to a 5 port switch which also houses my Xbox One and my Laptop.  I've tested the network speed, and the network is seeing in excess of 900mbps, so Gigabit close, so no issues via that route on the server. It's a strange one, I've even put out a message on the Plex Forums and DM'ed Chuck, and it's left him scratching his head to.... I do like a good challenge!!

Oh on Plex settings, I've got the relay switched off and the IPv6 also, nothing else changed.

Hope this helps?

Dave

[#5]

@mw0dcm 

For about 40 quid you could get a Raspberry Pi and then run Pi-Hole on it. Once installed, plug it into the router via ethernet, change a couple of settings and then you've an active blocking software working for you. I gather there's lots more you can do with it but I've never looking into it.

Brian

[#6]

@mw0dcm 

Have you considered moving the plex server to the DMZ?

Also does this help? https://support.plex.tv/articles/200931138-troubleshooting-remote-access/ 

[#7]

For a long time I've been remotely accessing our plex server without any problems.

[#8]

Hi all,
Ah, it seems from my findings that I'm on a CGNAT, looking at the IP address I've been given, so this may answer a double NAT issue? Hence why when I switch off the NAT on the Router and leave UPnP on it all works.
I'm going to look at the Raspberry Pi thing after Xmas and also upgrading my Plex Server, and opting for a clean install of Ubuntu 24.04LTS...

Cheers to everyone for their inputs on this thread, I've made notes etc. If it is a CGNAT then this definitely answers all?

Dave

[#9]

Ah, it seems from my findings that I'm on a CGNAT, looking at the IP address I've been given

Plusnet don't use CGNAT!. What makes you think you have a CGNAT IP ?

[#10]

@mw0dcm 

Post deleted, I should have refreshed before

[#11]

I'm only running the Plusnet Hub, nothing else in-between, but what makes me think it's CGNAT is having to switch off the Router NAT to make the ports etc too work, I can't find any other issues that would cause it as my firewall on Ubuntu is off, no other item is blocking anything.

Dave

[#12]

How exactly are you "switch off the Router NAT to make the ports etc too work" ?

[#13]

I'm going into the arcade settings on the router and switching the Firewall off, this cures the issue

[#14]

Sorry to be dense but what is the arcade setting on the router. Maybe you mean Advanced Setting?

Switching off the firewall does not remove the router NAT just opens up ALL your network to unsolicited traffic which is unwish

[#15]

Sorry, predictive text and kids running around... Should've been advanced settings then Firewall

That'll teach me!

Dave