Very strange router problem, I appear to be on neighbours Sky network

[#1]

I have a wireless router (Apple AirPort Extreme that creates two networks, 2.5 & 5ghz. We'll call it A. I have a static IP from Plusnet that is 84.xxx.xxx.xxx as I have to use one to dial in to a certain client of mine. Internally the IP range is 192.168.1.xxx.
This morning I tried to VNC to this client, last time I did this was at about 5pm yesterday evening. Couldn't get in and after a call to them to make sure they hadn't changed anything I tried whatsmyip. It showed mine as 90.xxx.xxx.xxx which was a bit odd. I tweeted my Plusnet to ask why they'd changed it & got the client to change the settings on their firewall. Plusnet claimed that they had never changed the IP & after a bit of too & froing it was established that it is still 84.xxx. Then a neighbour came over to borrow my printer, asked me to print out a file for her. I couldn't establish a connection to the wifi printer which has never happened, it's always been extremely reliable. This prompted me to scan my network, the scanner suggested looking at IP addresses starting 192.168.0.xxx which I thought was extremely odd but went with. At 192.168.0.1 was a Sky router. I don't have one of those. There were 3 Sonos devices as well, haven't got any of those either. The neighbour who wanted the printing done said that our new next door neighbour has Sky broadband. I typed 192.168.0.1 into a browser and got taken to the homepage of a Sky router that is creating the network 'TheWiFi'. Checked my WiFi settings again. My computer says it is on network A. My phone is on network A but has the same 192.168.0.xxx IP address. My sister has a Sonos so I have the app on my phone, I can control the neighbours device from my phone. I tried to actually join TheWiFi on my computer but was asked for a WPA2 password. I have no idea what the password might be, I don't even know the blokes surname yet.
When I use a wired connection to the router  I am back on network A with a 192.168.1.xxx address but no internet connection.
When I turned my router off I lost all connections, so I can't just hop onto his network when mine isn't working.

[#2]

Your neighbour may have an open wifi setup, so you are connecting to his instead of your own wifi.
I would check you wifi setuo and make sure that YOUR wifi is enabled and is set to the default connection, or it will just jump to the strongest "free" one.

[#3]

I am definitely selecting my own network, I have screen grabs as I couldn't quite believe what I was seeing! I have since killed my original network and made another, joined that and get the same result.
I also get the same result if I turn off wifi on my laptop and connect by ethernet directly to my router. How can that be happening?

[#4]

Here is a screen grab of Speedtest.net showing the IP and ISP. I am definitely with Plusnet.

[#5]

Your neighbours could be setting their router to the same name as yours, so you connect to theirs...
Rename your router, then connect to the new name (connect via wire to rename etc)

[#6]

Have you got any powerline adapters as part of your network?  Has your neighbour?

[#7]

I do have Powerline, Jesus, that's it isn't it? I use two Power Ethernet T1000 and a generic one to get my Humax PVR on the network.

[#8]

Bingo! 

[#9]

Quote from: pwatson

Have you got any powerline adapters as part of your network?  Has your neighbour?

That was exactly it pwatson, thanks a lot. I actually thought I had secured the Powerline network so will put that right tonight.

[#10]

Glad it's sorted .  Probably worth a word with your neighbour so that he changes his devices from the default settings as well.

[#11]

Just a quick question,
Im thinking of getting some powerline adapters, and I thought they only worked around 1 ring main?

[#12]

They work basically throughout a whole connected circuit.  Be that 1 ring or in my case, 3 rings - within the same connecting point of the fusebox.  The issue comes if you have a shared incoming mains supply - most semi's or terrace houses.  If so, then make sure you change the default user id as the link wire is close enough to pickup each others networks.

[#13]

I wouldn't advise powerline adaptors. The throughput through them can be very inconsistent and they interfere with your broadband.
I'd advise hardwiring if at all possible.

[#14]

I agree with AlecR - my powerline adapters injected severe noise onto the VDSL2 (broadband) signal and caused a high depth of interleaving.
Having said that, I see people posting who don't seem to have any issues with them, so I don't think it is a universal issue with powerline adapters, but it could be certain makes.
The actual adapters I had worked fine, it was only when I started monitoring my line stats, I could see the effect of noise. By removing them I increased my speed a little and improved the ping.
The solution I went for was one of the TP-Link wireless nano routers (about 16 pounds). You configure it for your wi-fi network and it has an RJ45 port on it. I have it behind my TV along with a little 4 port hub and can connect all my internet devices that way.

[#15]

@AlecR - I get the other extreme.  I get lots of inference from overlapping WiFi channels and on a usual evening snap-shot, can see 10+ networks (2.4 and 5) upstairs on my laptop changing channels every 30secs or so.  Whilst the powerlines do inject some noise in my case, it is not enough to overcome changing to a WiFi only setup.  I have tried both setups and the internet enabled TV and Freeview box much prefers an ethernet connection to WiFi. I do have the very small TP-Link 4 port hubs connected to by powerlines and can recommend them if you need additional connections or you should be able to find them with 2 or 3 ethernet sockets now.
@createdbydan - Pros and cons to both setups.  Only your environment can confirm which is best for you.