Problem with Plex/Chromecast since moving to TalkTalk

[seajays]

Hi - I moved to talktalk from sky a couple of weeks ago.

Since then I have been unable to cast from my plex media server to my chromecast devices due to an issue with secure connections.  I suspect that this may be due to DNS rebinding protection from the ISP in some way.  This document describes issues with DNS rebinding protection which may cause problems:  https://support.plex.tv/articles/206225077-how-to-use-secure-server-connections/#toc-4

I have tried using alternative DNS servers however and that has not worked,  it then goes on to describe scenarios with dnsmasq and pfSense DNS Resolver.

Could either of these, or something else be causing a problem.  Effectively I need to exclude plex.direct from any DNS rebinding protections, but I cannot see any settings on the talktalk hub (FAST 5364) to adjust that.

If I reconnect my old SKY router, everything works perfectly again.  Replace the talktalk one and it stops. 😕 

Any help would be appreciated.

Plex Chromecast Error Message

[seajays]

Thanks, I've been in touch with them and it seems, looking at logs etc., that as suspected, it is some form of DNS rebind protection that is built into the router which is causing the problem.  Unfortunately as the router is locked down, there is no way to configure an exception, so for now I've gone back to my old Sky router (which works fine), and have ordered a replacement router that will allow me more configuration options.

[KeithFrench]

Hi @seajays 

I do not have any experience with plex. Reading through the posts I can only suggest you contact their tech support.

[seajays]

Yeah - me too! 😅   Thanks for the suggestions though. 👍

[Karl-TalkTalk]

Hi

Ok, so it won't be this then.  I'm stumped on this one, not sure why it is not working.

Karl.

[seajays]

I don't use the wifi in the routers (it is switched off in both the old sky router and the talktalk one).  I have a seperate mesh wifi network, which is connected to the router via ethernet port.

[Karl-TalkTalk]

Hi

try separating the 2 wifi channels in the router.  Some older chromecast devices can have an issue. I know my early chromecast didn't like the wifi channels until they separated.

Karl.

[seajays]

Yeah it's very odd - everything else for Plex is working fine - I can play on desktop/app... it's purely when I try to use Chromecast.   If I simply swap the sky router back in again though everything works. 😕   I'm trying on the Plex forums also to see if there is anything there - otherwise I'll just have to swap back to the sky router (which is a shame as we'd just got the talktalk one working! 😄 )

[Karl-TalkTalk]

Hi

OK, not sure what this could be. I've made sure the router is now running the latest firmware, but  don't know of anything that would stop plex from working.  I've used plex in the past on my own TT connection with a sagemcom router and it worked ok.

Karl.

[seajays]

Yes, everything has been rebooted (s actually powered off/on - everal times!), Plex server, apps, WiFi, router, Chromecast. No luck.

[Karl-TalkTalk]

Hi

Have you also restarted everything, including the plexserver ?

Karl.

[ferguson]

OK, you have lost me there I'm afraid! My internal setup is far simpler and I know it works, that's all I can share, sorry.  Hopefully somebody else can come along and advise further. 

@KeithFrench Can you help here maybe, please?

[seajays]

Yes I suspect it's something to do with the "rebinding" protection described in the link above - although not sure if that explains why it works from other apps... Plex seems to do something interesting with the plex.direct domain which is meant to be sent via DNS to a local address.  At least that's my current thought!

[ferguson]

OK, I am a wee bit puzzled then. I thought you might need to revisit your Chromecast settings to make sure that it is connected to your new TalkTalk router, but If other devices and apps are connecting via that and are casting OK I can't think what else you might do. 

[ferguson]

OK, I am a wee bit puzzled then. I thought you might need to revisit your Chromecast settings to make sure that it is connected to your new TalkTalk router, but If other devices and apps are connecting via that and are casting OK I can't think what else you might do. 

[seajays]

Hi, sorry, should have said.  I have a terramaster NAS server on the local network running PMS.

All other connections to it work and playback is no problem, so PC/laptop browser can play fine.  Mobile app can play fine on the phone as well - just when you try to cast to any of our Chromecast from the app (we have two) it fails with that error.

It is not WiFi, as that is disabled in both my new and old router, as I have a mesh network which connected the same to either router.

Oh, and yes all other apps etc are casting fine to Chromecast (e.g. Disney+ etc)

[ferguson]

I presume you have your Plex Media Server installed on a laptop/PC, are you able to access the player OK via the web browser there? So is it just the casting feature that is failing? Are you able to cast from other sources to the Chromecast? I have been using Plex for years on my TalkTalk connection and have never experienced any ISP-related issues.