Ethernet 'one way' / 'device in use' problem

[ghubregtse]

Having spent probably 12 hours trying to fix my latest problem, it is time to ask for further advice...

System: Expert Pro 1000  - Roon on NUC - Synology NAS - switch (simple) - all ethernet wired
Connected to rest of house LAN via a hard-wired TP-link router configured as a wireless repeater
Connected to main router (now new Draytek) - hard-wired

This physical setup has worked really well for last 2-3 years (apart from the occasional minor Dev issues which we are all familiar with). Until I replaced the standard TalkTalk router last week with a dual-purpose DrayTek which combines the normal ADSL line with a G4 connection (using an unlimited data SIM inserted). This was done, as our 4G signal is about 50-80Mbps, versus the landline about 8-12Mbps. Apart from the issues with the Devialet, it all works really well; we now have home internet, wired and wireless, which is 5+ times as fast as before.

However, this has completely scuppered my Roon/Dev setup - I continuously get the 'Device in use'/'Roon lost control because input was switched' etc error messages whenever I try to play a track. No exception. No streamed music at all, whatever I do. I have trawled the Roon and Dev forums and these messages appears to be a fairly common issue - but from what I can gather, usually intermittent.

I have done the following, and nothing has changed the situation:

- Discovered the latest Dev firmware and uploaded it (without a problem) - 13.2.0 
- Tried both fixed and dynamic IP addresses for Expert Pro
- Reverted to firmware 13.1.3 (again uploaded without a problem)
- Ensured wifi is turned off in the configurator
- Checked that vinyl and analogue line inputs work properly; they do, Dev plays them fine
- Done multiple full power offs (turned of at wall socket and waited for a few minutes)
- Disabled and re-enabled Ipv6 on the new router
- Reloaded Roon's operating system, all settings and connection to NAS, cleared caches

'Diagnostic':
- As suggested in a thread somewhere, downloaded the Remote app onto my iPhone. Interestingly, the ethernet connectivity problem appears to be only 'one way', i.e. towards the Expert Pro. When e.g. inputs or volume levels are changed using the (aluminium) remote, this is reflected on the iPhone app display. However, any commands made from the phone remote have no effect (e.g. volume change, input change or power off). So, it appears there is some connection via Ethernet.
- The router recognises the presence of the Expert Pro in its connected list, correctly attributing either a fixed or dynamic IP address as requested.
- The Roon setup as such seems to be working fine; it recognises the NAS, accesses Tidal and Qobuz, and successfully plays them through e.g. my iPad or phone when requested. It recognises the presence of the Expert connectable by AIR in its 'Audio' settings (also with Airplay as a separate option) and allows me to request connection.

I would be most grateful if anyone could suggest a further approach. I am not desperately keen to go and rip out the new Draytek router, as absolutely everything else about it is absolutely fine, and it is a huge improvement...
Should I consider USB connection...?

Thanks in advance for any brilliant suggestions!

[Delija]

Firewall settings?

[ghubregtse]

I must confess, I am no firewall expert! Would a firewall create this problem within the LAN behind it? What do I need to look for?
Thanks for starting the ball rolling...

[thumb5]

It might also be worth asking Roon support about this. [ETA: I see you posted on the Roon forum as well - hopefully Roon support may chime in.]

Could this be something to do with multicast support on the Draytek?  It probably has options to control IGMP proxy and/or IGMP snooping, both of which are mentioned in Roon's Networking Best Practices document.

[ghubregtse]

That's very useful... I will investigate, thanks

[Delija]

I must confess, I am no firewall expert! Would a firewall create this problem within the LAN behind it? What do I need to look for?
Thanks for starting the ball rolling...

Check whether the firewall is active on router.

[ICUDoc]

Power cycling the Dev by turning off and UNPLUGGING is necessary for me. If I don't unplug it doesn't work! (how weird is that!). Leave unplugged for 2 minutes or so.
If it doesn't work immediately, then I doing it a second time, which almost always works.
Other trick is to change the Ethernet settings on the Mac mini then change them back (not sure if applicable on NUC) and finally unplug the Ethernet cable while in use then plug it in again.
Simple reset on the router?
Good luck

[ghubregtse]

Managed to solve the problem - thanks everyone for their contributions!

I have reconfigured the secondary router (TPLink) to act as a router again, rather than an access point. The Primary router (DrayTek) is connected to it in a LAN to WAN configuration, with all the IP addresses on the secondary network now in the 192.168.0.x format (as opposed to 192.168.1.x on the primary network). The internet access on the secondary network is therefore the same as on the first, providing much better streaming and upload speeds. And, the Expert Pro is happy!