My Sagemcom FAST 5364 Router seems to be broadcasting an additional 'hidden' network

[Pegasus]

Hi,

While using a wi-fi scanner to locate interference free channels on the 5GHz frequencies, I noticed another hidden network on the same channel as mine (36+40+44+48). When I changed channels on my router to avoid it, it followed me to the new channel. When I moved back, it moved back as well. It seems my router is broadcasting a hidden network, because when I turn the power off to the router the hidden network disappears. I cannot use the normal 5Ghz network without the hidden network also being broadcast at the same time. It is possible to turn off 5Ghz to disable the hidden network, but obviously then my 5Ghz network no longer functions.  Have you any idea why this hidden network is being broadcast, could it be something to do with the guest network function?

Many thanks for any replies, 

Pegasus

[KeithFrench]

I thought I explained before, the router at this firmware level sends the hidden SSIDs out in case you are going to use it as part of a mesh. It is the necessary backhaul network in case you later add a mesh node. It cannot know what your intentions are.

[vadek]

Yes, I did read the whole thread before posting, but my router is not part of a mesh and the guest networks are turned off. The ghost networks were never there before so I don't know why they would suddenly pop up.

[KeithFrench]

Please see my previous post back on the 8th of July, which answers your question.

[vadek]

I discovered today that my TalkTalk hub (FAST 364) was broadcasting two identical networks to my 'official' ones on exactly the same channels (9 and 48). Both networks were called *** in my WiFi Analyzer app. I say 'were' because I rebooted the hub and they seem to have disappeared (whew). This is worrying me a bit because of possible security issues. I checked all the advanced settings on the hub and I can't see anything that would explain these two mystery networks. Both the 2.4 and 5 band Guest networks are off. I'm going to have to check what's it's broadcasting more regularly from now on.

[KeithFrench]

Both the 5364 and 266 send out different hidden networks when used as mesh. Each one forms the 5GHz backhaul network for inter-mesh node communication & internet access. If you have enabled the guest networks as well,  you will have another set of user networks & everything will all be on the same channel most of the time. Channels 36 - 48 will change around depending on what usage they are being put to, this is one way that the 5GHz band helps to reduce WiFi interference

If you want any help on the mesh, please ask me.

[Pegasus]

Hi,

To anyone following the story so far - according to TalkTalk Devices Team:

•     "This ‘hidden’ SSID is there for the TalkTalk Wifi Booster (Sagemcom F266), it’s a backhaul SSID for the booster. The only device that could connect to this hidden SSID is the TalkTalk Wifi Booster"
•    "This is by design and cannot be disabled"

I guess you just have to accept if you have a Sagemcom FAST 5364, it will be broadcasting a separate 'hidden' network on 5GHz that you cannot disable - unless you switch off 5GHZ completely.

Bit of a shame, but at least the mystery has been solved.

I am very grateful to all who recommended solutions and offered to help 🙂

Many Thanks,

Pegasus

[Chris-TalkTalk]

OK, please let us know how you get on

[Pegasus]

Hi Chris-TalkTalk,

Thanks for replying. 

I'm afraid I do not have any power line adapters or boosters or anything, it is a very basic setup, just the router and wired connections. The mac address of the hidden SSID is only one digit different from the other wi-fi mac addresses on the router, and the signal strength tells me it's coming from the sagemcom.

I will attempt a factory reset as Debbie-TalkTalk suggested, when no-one here needs the internet.

Cheers,

Pegasus

[Chris-TalkTalk]

Hi Pegasus,

Just a thought but do you have power line adapters?

Chris

[Pegasus]

Well, this is very odd... Nobody seems to know what my router is doing, including the people who sent it to me. Thanks to 'DaveWillow' and 'mrmos' for your suggestions, but like I mentioned previously, when I turn the power off to the router the network disappears. Also the signal strengths prove it is coming from my sagemcom. I may post the question in the "security" forum as I am concerned for the safety of my network.

Cheers,

Pegasus

[mrmos]

Google chromecast or similar in your network?  Just a thought.

[Pegasus]

When setting up my network I originally named the two networks:  'sun' which is the 5Ghz, and 'moon' being 2.4GHz.

I have added some screenshots from Tarlogic's Acrylic Wi-Fi analyser. I also recently enabled the guest networks to see how they appeared on Acrylic.

You can clearly see this mysterious "hidden" network is originating from my talktalk router as the signal strengths are much higher than any neighbouring wi-fi networks (the five mac addresses are also very similar as expected) also they all disappear when the router is powered down.

Still confused what this hidden network is doing and have temporarily disabled 5GHz.

Thanks

[DaveWillow]

Hi Pegasus, have you thought that it could be someone else's router. On some routers, there is an option to 'hide' your SSID. As far as I'm aware you can still connect to it, although you may have to enter the settings manually. Turn off your router (by the router settings if possible), then use a phone or tablet PC, or a PC (I'd give it about 5 minutes to refresh on your device). See if the hidden network is there now. There are a number of utilities you can use, including Fing (not sure if I'm allowed to say that). This will show you the available networks including the hidden one. If its not there ...

[Debbie-TalkTalk]

Hi Pegasus

I have split the SSID's on my router because my printer will only connect on 2ghz. So in my wireless list you can see both 2ghz and 5ghz and can connect to either.

If you haven't split the SSID's then it should just show your router name in your wireless list. Have you tried factory resetting the router using the pin hole reset for ten seconds?

[Pegasus]

Hi Debbie-TalkTalk,

Thank you for replying to my question so quickly, it is much appreciated. But I am still not clear what this 'hidden' network is for. What is the actual SSID, what is the password, and who connects to it? Why does my router broadcast this network, what is it for? There seems to be little information available, and this feel like a security risk when I have no idea what it is.

Thank you,

Pegasus

[Debbie-TalkTalk]

Hi Pegasus

I can switch the WIFI optimisation off so you can choose your own wireless channels (and it will stay on the selected channel)

Would you like me to arrange this?