Thanks for the replies. I think it should have worked, but it didn't, and I'm very confused about this.
Basically, when I had my apartment decorated, I asked them to put in a LAN, with ports in 1 bedroom, living room, and the rest in the office. I had presumed that all the RJ45 ends would terminate in my office, and I could just put them into my Asus RT-AC88U wireless gigabit router, which has 8 ports.
Unfortunately, they terminated in this small cupboard in my bedroom, where the fibre-to-the-home fibre also terminates. So this meant I had to install the FTTH modem here, connect one RJ45 from this which connected to one of the LAN faceplates in my office, which then connected to the WAN port of my wifi router, so all my WiFi devices now had internet access. But then I had to connect another RJ45 from the WiFi router into another LAN faceplate, and then connected all other RJ45 terminations in my bedroom into a D-Link gigabit switch. Extremely messy, but I didn't know how else to do this. It also works as it should.
What I noticed when they installed the new FTTH modem, is they plugged the IPTV box into this, rather than the Gigabit switch.
I also noticed some really weird things going on with IP addresses.
The FTTH modem seems to have the IP address 192.168.1.1.
My Asus wireless router has the IP address 192.168.2.1.
All other devices on my LAN and my WiFi have the IP addresses 192.168.2.x. This includes TVs, two PCs, a laptop, Synology NAS, phone, printer, etc.
However, the TV box has the IP address 192.168.1.2, because it is plugged into this FTTH modem/router thing. So, I think, no problem, I'll just unplug it from here and plug it into the Gigabit switch, then my WiFi router will assign it an IP address of 192.168.2.xx, and it will work fine. But it doesn't. It gets stuck with the message
网络问题:获取IP地址失败或失效,建议重启光猫, 光猫启动稳定后,重新启动机顶盒,如还有问题拨打联通客服电话
产生错误原因,DHCP获取IP 地址失败, 包括DHCP 续租失败。
Which basically means DHCP failed to get an IP address.
From my PC (192.168.2.156) I can ping 192.168.1.1, the FTTH modem
I can ping 192.168.1.2, the IPTV box
I can also ping 192.168.1.3, which I wasn't initially sure what it was.
So I logged on to 192.168.1.1, the FTTH modem, to try to see what that device was. 192.168.1.2 has the same MAC address as the IPTV box. 192.168.1.3 has the same MAC address as my Asus WiFi router!! So now I am completely confused, as I know the Asus WiFi router has the IP address 192.168.2.1 !!
So I logged on to 192.168.2.1, and at the top of the screen I have Internet Status: Connected. WAN IP: 192.168.1.3.
I am so confused. I thought the WAN IP would be the IP of the FTTH modem, which is 192.168.1.1?
I tried to log on to 192.168.1.3 but nothing opens.
So to go back to my original problem, I can only get this IPTV box working on the bedroom TV (which doesn't have a network port in that room) is to get it working on the 192.168.2.xxx network, but it doesn't get assigned an IP address when I plug it into the Gigabit switch (where other devices on my network do).
Here's a sketch of what I'm rambling on about:
I'd be so grateful if anyone can shed any light on this and clear my confusion!!