Hello again,

Ah I did not realise your ISP router had a modem mode, this gives us another avenue to approach the problem, as far as I see it there are three options

1. Have a look at your ISP routers settings there may be a way to disable just the wireless radios without putting it in modem mode, depends on the router though and without the model I am unsure if its doable on your router. This would mean you still use your ISP router for routing, DHCP, DNS etc. but the WiFi connection comes from the decos.

2. Depending on your model of deco you probably have a spare ethernet port or two on the main deco (that's plugged into the ISP router) if that's the case you could buy a cheap unmanaged switch, something along the lines of this: https://amzn.eu/d/dJ3tq1P this will plug into one of the spare ethernet ports on the Deco and act as an 'extender' so you can plug multiple devices into the switch and then the switch into the deco. Then you would reverse what you did on the first post, by gong to the deco app More -> Advanced -> operation mode and selecting WiFi router, after this go to your ISP router unplug all the ethernet devices apart from the deco (and make sure the deco is in port 1) and enable modem mode. This means your ISP router is now a dumb modem and all routing, DHCP, DNS etc is handled by the deco (so if you ever want to port forward it will all be handled by the decos via the deco app and you no longer use your ISP routers admin page). This will still have all your devices on one flat network as it is now and will avoid the double NAT issue.

3. You do nothing, as long as your not noticing WiFi degradation when your near the ISP router in theory it should cause no issues. If you do choose this option I recommend you go to on the deco app More -> Network Optimisation and run through that, this will make the decos try and find a wifi channel that is not busy, meaning it will in theory put your decos on a different chanel to the ISP router and attempt to avoid clashing.

Let me know if you have anymore questions but if you not, hope that helps!

If you’re starting the mediabox setup on the isp network, it’s doing local natting with iptables, based on the IP that it resolves from the hostname. Probably would need to shut down and re-up to walk between the deco’s and the isp wifi domains.

I agree with the other comments, looks like you might be in a double NAT scenario - fortunately for you, I think I know how to fix it, seeing as we’re both running deco’s!

You want to go into the smartphone app, go to ‘More’ at the bottom right, (as opposed to ‘Network’), Advanced > Operation Mode > Access point.

Be aware this will cause a disruption, and anything connected to them will need to be reconnected so it gets dhcp/ip addressing from the isp router rather than the deco.

The other alternative is, if they’re already in AP mode, it might be recognizing the deco SSID as a separate network to your ISP’s router, and randomizing your mac address (for anonymity across airports and hotels and such). Then, with your original mac address holding the first IP in lease, your ‘new’ mac address gets a different one. Check your mac with ip link too when connected to the two different networks, and see if you can find an option to set it manually for both networks, or just use your default one for those networks.

I’d love to hear how you get on, I’ve been putting off building this exact solution (mediabox) from scratch, had no idea there was a project set up to run it all