Sorry not to have replied before, but haven’t been at home.
Update: I have two Asus RT-AC68U wifi routers, one acting as a proper DHCP router which has Open VPN using Nord protocols, the other just acting as a node to provide a mesh throughout the house. There are cat5 sockets in most rooms, wired into a Cisco Catalyst switch bar which is in turn connected to the Asus router, so my home network is a mixture of wired and wifi connections. The garage and a store room have walls of thick stone and reinforced concrete, so I have a WAP wired in to each, allowing me to access my internet from a phone in the car (and thus see whether the road is clear when I pull out from the garage). All this has worked well hitherto, most recently with a Cat5 cable between my Asus router and a Numericable router from my fibre ISP (SFR) running in modem mode disabling DHCP. Cat5 cables connect my Asus router to my smart TV, and my Sky box connects to my Asus router using wifi.
Orange was installed last week, using a Livebox 5 router which is a lot more clever than the Numericable one. I explored the GUI of the Livebox and found no indication of how to set it to modem mode. There is a tick box to enable DHCP, but it seems to have no effect, whether ticked or not any device connecting to the Livebox gets an IP address in the range 192.168.1.2 onwards. I reset my Asus router to factory settings, then set up my logins and SSIDs on the Asus GUI, and reset the Livebox. I set the Asus router to use 192.168.2.1 onwards. I spent a day or so on this, resetting each router several times, while tearing my hair and consuming too much coffee. Whatever I did, the Asus router was not connecting to the internet.
On the Livebox I reserved 192.168.1.10 for the Asus router’s MAC address, but still wasn’t quite there. At this point I should emphasise that I’m not, and don’t pretend to be, a Networks guru: when I was leading an IT helpdesk before I retired, I was Desktop side, and left network technical work to the specialist team, so by this stage I was a bit out of my depth. Anyway, I then tried setting the Livebox’s IP range to 192.168.1.11 onwards, so the Asus router wouldn’t be affected. I rebooted each router whenever any setting was changed. I was getting nearer now, and set the Livebox to the lowest firewall setting. I began to relax a bit by then, and set the DMZ on the Livebox to let the Asus router’s IP address through.
After the next reboots, the Asus router at last had internet connectivity, and I set up Open VPN and installed the Nord protocols. I had, as one does, kept a list of all the steps I had taken, so edited this to remove all the steps which hadn’t had any effect, so that if I ever have to set up a successor to my Asus router I will have a less frustrating time!
At least I now have the ability to download programmes via Sky Catchup on the Sky box and Sky GO on a laptop, and can use individual catchup facilities for UK channels on the smart TV. There are sometimes error messages as if there are intermittent losses of internet but a second attempt usually works. Now I have to set up my port forwarding so I can view the CCTV and IP cameras from the UK , and reinstall both the video doorbells. I have performed a couple of IP scans to identify which devices still aren’t on line yet and will work through them during the coming week.
If any expert out there has any advice as to anything else I should be doing to provide a stable network, I’m all ears. Thanks for your support, all those who have already replied. I did research the Orange customer support web pages, but I seem to be the first amateur Orange customer to try this configuration.