I have tried to get the CS3 web server to work on my PC – wirelessly.

But I don't know what I'm doing wrong. It worked 14 days ago – now it has suddenly stopped working.

This is the equipment I need to have working together:

The router in the house.
PC (with wireless internet connection via the router in the house)
Märklin CS3
A TP-Link nano router, which is physically connected to the CS3 (network cable + power)

I have previously – with enormous difficulty (took me two days) – set up the nano router to "talk" to the house router, so that the CS3 works (or should work) as a device with its own wifi (as I understand it). After that, I should "just" be able to enter the CS3's IP address (192.168.0.131) into the browser, after which the CS3 screen should appear in the browser. The problem is that it doesn't…

I don't know if I should start from scratch setting up the TP-Link nano for the house router, or if I can troubleshoot the existing one.

I have absolutely no idea what IP, DNS, DHCP, TTL, HOST, PROXY etc. are, how they work together, or why. I just need to know exactly WHAT to do, know exactly WHICH numbers (IP addresses) I need to use, and exactly WHERE to write them.

In another forum I specifically asked for these things to be explained – instead I got 3 writers' 2-page descriptions of how computers, IP addresses, wifi, routers etc. work – but I wasn't any closer to solving the problem. It was like asking what 2 + 2 is – and instead of getting the short answer (= 4), I got an explanation about the origin of the number system in India in the 6th century. Educational, maybe. Helpful, not at all...

That is exactly what he wants, the cs3 to talk wirelessly to the house router.

I am not familiar with the TP-Link nano, but I have a similar style of link for my PVR, so that I can connect it to the house router to do internet connections without having to run a long cable up the stairs where it would get in everyones way.

I use one of these to provide the wireless link to the house router. To set it up I first looked at the wifi settings of my laptop, and noted down the values of the four fields given above. Then I turned off the wifi on the laptop, and used an ethernet cable to connect to the Vonets device. I can't remember the exact sequence (the instructions for the device will tell you) but I opened a web page on the device and entered the appropriate values in the four fields, and saved them - except I used a different address to the laptop by altering the last digit set of the IP address, so where the laptop had 192.168.0.30, I set the Vonets up to 192.168.0.100 so it was well out of the range of the DHCP addresses. Once that was stored I then moved the Vonets to to the PVR, connected to the ethernet port, and allowed the PVR to access the wifi, and to get an address using DHCP.

Now, you haven't mentioned what model of TP-Link nano you have, so I cannot check if it is designed to work in the manner you want, so maybe you could tell us that bit of info first. When I go looking there are a whole heap of different models for different purposes listed under TP-Link nano.

He is attempting to access the web page on the cs3 from his PC. That is a perfectly legitimate way to have a PC talk to a cs2 or cs3. The web page then shows what is on the cs screen.

If you are trying to use the pc as a mirror of the CS3 with all of its features and you did that successfully fourteen days ago then you should be able to do it again unless you changed something like the connections. As stated above the TP-Link needs to be turned on and working before the CS3 The sequence might be important and I am not certain of the sequence for the pc. But definitely the TP before the CS3. And then launch RealVNC on the PC. Hopefully you have the free version of that through Marklin otherwise it is possible your free 30 day offer expired. Then you would need to delete it from your pc.

I am not sure but it is possible that your device is only a repeater/extender. It picks up a signal from the house router and re-transmits/boosts it. You might want to check with TP-Link customer service to see if that is the case. My TP-Link router has antennas and lots more sockets. And it works. I just checked out the manual and it is might be possible to set up the router the way you want but you probably have to reset it to factory setting and then follow the instructions for resetting it. But I don't know which instructions you need to follow.

It does list "Client Mode" under the specifications here. On that basis I would have thought it would do bridging to the router.

"It does list "Client Mode" under the specifications here. On that basis I would have thought it would do bridging to the router." Yes, I saw that but is it assuming the house router has wifi input? I am sure mine has. It was provided by Xfinity and I am fairly sure it is hardwired to the internet while transmitting and receiving wifi signals.
Typical that he does not answer any of our questions. Is the RealVNC app on his pc? What is he trying to use the pc for? If the TP-Link is connected and acting properly he should be able to connect via smart phone but that also requires a smart human.

We need some more information to help. How about a little sketch of your setup? From what I understand, it looks like


PC
|
| wireless
|
router
|
| wireless
|
TP-link
|
| wired
|
CS3


Depending of your subnet mask, 192.168.0.131 and 192.168.0.120 may not be in the same subnet and thus unreachable.

Does your PC (e.g. "ping" ing or in your browser) "see" the router? The TP-Link?
What's the router's IP? The TP-link's IP?
If admininstering the router, you might see the entire network setup. Do TP-link and CS3 show up?

You can obviously connect a CS3 to a pc with an ethernet cable but I think they can not communicate together. Otherwise there would be simple instructions on how to do it. I think the first thing he should do is figure out how to set up his TP-Link as a router and connect to it with a smart phone or pad. Once he does that and has learned about passwords and ips he can then try to do the same with RealVNC. The wiring is simple - ethernet socket to ethernet socket. Turn on the router before the CS3. Find the network with a smart phone and enter the password. Then find the QR code on the CS3 and "photograph" it with your phone. Or enter it into your browser. Once he has successfully done that he might be ready for the more complicated setup but the smart phone needs to be operated by a smart human.