topic Zyxel VMG3925 WiFi problems with new devices in Tech Help - Software/Hardware etc

Zyxel VMG3925 WiFi problems with new devices

flamesong — Tue, 08 Dec 2020 16:34:59 GMT

I am reluctantly using the supplied Zyxel VMG3925 as the Netgear D6400 I bought to use cannot reconnect when the connection drops without being manually rebooted. I haven't got the patience or resources to keep buying routers until I find one which works but if anybody recommends one which works with Plusnet (John Lewis), I'll consider investing.

That out of the way, I have been managing to use the Zyxel VMG3925 despite its oversimplified yet awkward interface until recently when I bought a new Philips television which I use pretty much exclusively for online use (there is not even an aerial connected to it). I also bought a Roku Premiere but despite the television and the Roku being only 2m from the television (and both showing maximum signal strength), there have been constant WiFi connection problems. There are other devices, including another television and Roku, throughout the house (some with two walls between them and the router) and none have any WiFi problems for years.

The Philips television says that it cannot connect via WiFi about 75% of the time I switch it on. I try via 2.4GHz and 5GHz and if I am lucky, I sometimes get a warning saying that a connection has been established but it is 'restricted'. If I had connected via a guest network, I might understand that but I am only connecting to my main networks.

The Roku is much worse, maybe only 10% of the time I can connect and then the connection drops after maybe 20 minutes.

It's ironic that I have to go upstairs to use the Roku and television my bedroom which is four times as far from the router to watch a certain scheduled programme.

I phoned Plusnet today and the guy I spoke to kept going on about how Plusnet cannot guarantee connection speeds and I kept saying that this had nothing to do with connection speeds, it was about WiFi connectivity. When I finally got him on topic for a moment, he said that the television and Roku must both be faulty (the only two devices in my house which don't work and just both are brand new and both happen to have exactly the same problem) he told me that I shouldn't use the 5GHz WiFi as the router is renowned for being unreliable on that band.

I really hate using the Zyxel interface, it's like the AOL of router interfaces. Until recently, I have used D-Link or Netgear routers and have known my way around the settings but the Zyxel seems so clumsy. As I said, if I knew of a (definitely) compatible fibre router, I'd buy it but the last one actually had 'Plusnet approved' printed on the box but with spates of several dropped connections per day at the time, having to reboot the router every time was irritating to say the least.

Re: Zyxel VMG3925 WiFi problems with new devices

jab1 — Tue, 08 Dec 2020 17:22:08 GMT

@flamesong If you are with JL broadband then this should be directed to them - Plusnet are not your ISP, and I doubt their first-line support even know much about the Zyxel.

Re: Zyxel VMG3925 WiFi problems with new devices

flamesong — Tue, 08 Dec 2020 18:18:07 GMT

John Lewis Broadband IS Plusnet.

Phone John Lewis Broadband Customer Support (which I did) and Plusnet answers the phone (always).

Same address (John Lewis Broadband, The Balance, 2 Pinfold Street, Sheffield, S1 2GU), Same hold music, same staff all with Yorkshire accents. Even my Netgear router knew it is the same company; probably from the IP address.

Try it: 0800 022 3300.

Re: Zyxel VMG3925 WiFi problems with new devices

jab1 — Tue, 08 Dec 2020 18:31:00 GMT

OK The address is the same, the phone number isn't . In any case, and I meant to add this to my original reply but got side-tracked, an ISPs responsibilities end once you get a signal to your router.

There is no way even their top technical guys can sort out problems with YOUR equipment - there are way too many variables involved.

No ISP will offer guarantees over Wi-Fi either, again too many variables.

Re: Zyxel VMG3925 WiFi problems with new devices

MisterW — Tue, 08 Dec 2020 18:37:24 GMT

Have you tried changing wireless channel manually on the router ? In my experience the 3925 can be a bit iffy with its channel selection. It tries to find a channel with least interference from adjacent routers but sometimes doesn't get it right. I'm also not sure it adjusts if additional routerscappear after its done its checks. I'd suggest using a wireless analyser app to see what other routers are nearby and try manually setting the 3925 to use the least used one. Bear in mind that on the 2.4g band only channels 1,6 and 11 are non overlapping. On the 5g id suggest moving in to the 100s as most routers seem to pick the lower range.

For example I've got 2 routers close by and they're both using the default ch 42, so I've set mine to 106, well out of the way

Re: Zyxel VMG3925 WiFi problems with new devices

flamesong — Tue, 08 Dec 2020 20:23:58 GMT

The router is provided by the ISP when I renewed my contract. They should have technical knowledge on the equipment they provide.

The phone number is only different to filter JLBB callers from Plusnet callers. One CS guy once answered the phone Hello, Plusnet, xxxx speaking, can I start by taking your username.' to which I said, 'don't you mean John Lewis' to which we both laughed and he said that it had been a long day and explained that it is the same call centre.

Re: Zyxel VMG3925 WiFi problems with new devices

jab1 — Tue, 08 Dec 2020 20:45:44 GMT

As I have said - an ISPs responsibility ends when you get a reliable and useful connection to your router. They cannot be expected to know what you have connected your side, or to know how all this equipment works.

Thanks for the info re; the call centre - I wasn't aware of that.

Re: Zyxel VMG3925 WiFi problems with new devices

flamesong — Tue, 08 Dec 2020 20:47:14 GMT

Thanks for the advice.

I changed it to channel 6 earlier (clicked apply) but when I went back to check just now it was back on Auto. I've just tried again I'll see how that goes when I have a look later.

Changing the 5GHz channel is a bit more problematic as my MacBook Pro can't connect to the higher channels - it sees the network but when I try to connect it says that the network cannot be found.

I hate troubleshooting on this router because every applied change seems to cause the router to restart.

Also, on a different note, I have a number of devices on static IPs like my NAS so that I can access them from their IP on the network but unlike any other router I have ever used, I have not found a way of viewing an editable list of all rules - unless the device is on and connected. There is a NAS which I no longer own whose static IP rule I assume is still there but I can't delete it.

Re: Zyxel VMG3925 WiFi problems with new devices

flamesong — Tue, 08 Dec 2020 20:56:42 GMT

Regardless of whether the ISP should offer technical support using the equipment that they provide (about which, I respectfully disagree with you), I posted my problem here on this forum in a section which has the title, 'Tech Help - Software/Hardware etc'.

Re: Zyxel VMG3925 WiFi problems with new devices

jab1 — Tue, 08 Dec 2020 21:03:48 GMT

OK I was only trying to point out that an ISP cannot realistically help with equipment connected your side of the router, but just before I walk away from this topic - you say you already have similar equipment connected with no problems, so to my mind, the problem is your new equipment - not the router.

Re: Zyxel VMG3925 WiFi problems with new devices

Mustrum — Tue, 08 Dec 2020 23:05:13 GMT

If the router is that close to the TV and Roku, why on earth are you not using an ethernet connection?

If you must use WiFi, have you checked with a scanner which channels are free, or least congested. Make sure 2.4 and %Ghz SSID;s are seperate names. Makes sure there are no other devices that could interfere with the WiFi - cordless phones, and so on nearby.

Re: Zyxel VMG3925 WiFi problems with new devices

flamesong — Tue, 08 Dec 2020 23:32:18 GMT

I've thought about it. As far as the television goes, it is mainly aesthetics - there are no visible wires - but also, there are only four Ethernet ports. Three are already in use and I like to keep the fourth one as a standby with a trailing cable I can access without having to disrupt everything. As far as the Roku is concerned, it doesn't have Ethernet.

All networks have discrete names. Two private (2.4GHz + 5GHz) suffixed T and X, two guest (ditto) suffixed N and Z.

I live in a remote area with a neighbour right next door one way and my landlord's house is about 100m in the other direction so there isn't much congestion. There are no cordless devices in the same room.

I may check with a scanner tomorrow, I have other stuff to deal with right now, but I only see mine and my neighbour's networks.

Re: Zyxel VMG3925 WiFi problems with new devices

flamesong — Wed, 09 Dec 2020 12:14:13 GMT

I did a WiFi scan and just saw my neighbour's BT network on channel 11. Oddly, none of my four SSIDs are visible so I wondered if I had accidentally made them invisible but the hide box is greyed out saying that hiding is not possible using WPS 2.0 - which does not explain why the scanner cannot see them.

I managed to get the channel 6 change to stick which seems to work with my Mac but when I changed the 5GHz from auto to 108 (or several other channels which I tried later) my Mac was unable to connect via 5GHz. It would be 'trying' for ages then ask for my password (which is stored) and then reject it. Then, annoyingly, it wouldn't connect via 2.4GHz either until I had disabled then reenabled WiFi.

If my girlfriend didn't have an important Zoom meeting this afternoon, I'd be reinstalling the Netgear D6400 and tolerating its comparatively minor issue. I just saw that Netgear released new firmware for it last week so there is a possibility that the reconnection issue got flushed even if it wasn't addressed directly. At least I will feel like I have a little control over the router's behaviour.

Re: Zyxel VMG3925 WiFi problems with new devices

MisterW — Wed, 09 Dec 2020 12:37:29 GMT

At some point when you've got more time, you could always try using the 3925 as just a modem (bridge mode) and connecting to the WAN port on the 6400. That might solve the reconnection problem and allow you to use the better control of the 6400

Maybe the Mac can't support 5ghz Band B https://www.digitalairwireless.com/articles/blog/a-quick-guide-to-5ghz-in-the-uk-part-1

Re: Zyxel VMG3925 WiFi problems with new devices

flamesong — Wed, 09 Dec 2020 13:30:10 GMT

Yes, I think you may be right about band B. When I first got my this MacBook Pro, I couldn't connect it to 5GHz at all despite a year older MBP having no problems. I wiped it (it was second hand) and cloned the other MBP's HDD and it worked fine but I hadn't thought any ore about it once it started working but it has always been connected to the 5GHz network since because I do a lot of network transfers and whilst the speed difference is immaterial when there is a DSL bottleneck, copying 100GB from the NAS makes a lot of difference.

Why not use both routers in bridge mode? Well, clutter, mainly but simplicity, secondarily. The television is mounted on the wall with no visible wires and the router sits on a small unit along with a NAS, femtocell with their spaghetti spilling into a corner behind a sofa where there is a UPS and all the ugly secrets hide.

I've been looking into Zyxel this morning and found nothing to persuade me not to eliminate it from the system.

Re: Zyxel VMG3925 WiFi problems with new devices

MisterW — Wed, 09 Dec 2020 14:21:39 GMT

Out of interest, is the Zyxel a -B10B or a -B10C ?

I've been using the B10C as a trial for a while now. Whilst the GUI can be a tad sluggish at times, I've not really noticed any issues other than the wireless channel auto selection. Certainly I don't recall most of my changes requiring a reboot.

Its certainly MUCH better than the standard PlusNet Hub one, the modem is better and at least you can set your own DNS servers.

I understand your point about using both routers though. Before the Zyxel I was using a TP link 9970 as a modem in front of a Draytek 2830.

Re: Zyxel VMG3925 WiFi problems with new devices

flamesong — Wed, 09 Dec 2020 15:57:14 GMT

It's a B10C. I didn't include that bit as I thought it was a regional variation. Frankly, I know nothing about Zyxel products - I was guessing.

I'm not 100% sure that the router is rebooting but for about 2m the interface is unresponsive and inaccessible and there are no networks (apart from my neighbour's) in my WiFi menu whenever I apply ANY changes. There may well be functions within the interface that I cannot access. My browser of choice is Brave but after trying Safari and others all of which reported errors when I tried to change settings, I had to download Chrome to do anything - so it wouldn't surprise me if bits are not loading properly.

Funny, since changing to channel 6, websites are taking a couple of seconds before they begin to load so I checked the DNS settings (I had been using OpenDNS on previous routers) but even that seems to be simplified only allowing one IP address per server.

I didn't have problems like this before JLBB/Plusnet upgraded my connection to fibre (in order to mitigate the monthly payment increase when my contract ended) which meant that I had to get a new router as my trusty ten year old Netgear DGND3300v2 would no longer work. I took one look at the interface of the Zyxel that they sent me and went shopping for a fibre modem router which didn't look like an alien landing module and hence bought the D6400 which at least only looks like a slice of the 2001 monolith. My download speed has barely changed, by the way, upload is better but half what was claimed.

Re: Zyxel VMG3925 WiFi problems with new devices

MisterW — Wed, 09 Dec 2020 16:25:40 GMT

The B10C is the latest one being used for JL customers. The SU's(Superusers) were asked if we would like to trial them back in March when they started shipping. They don't support IPTV and so can't be the standard router for Plusnet customers who may subscribe to Plusnet TV. The interface is not the worlds best looking, I agree, but it does seem to be functional.

I currently use OpenDNS and am not seeing any problems.

My download speed has barely changed, by the way, upload is better but half what was claimed.

Do you mean the download hasn't changed fom the ADSL speed ?

What does the router show in the xDSL stats ? and what does 'Current Line Speed' show when you login to the member centre and click the Broadband tab ? and do you have a static IP ?

Re: Zyxel VMG3925 WiFi problems with new devices

flamesong — Wed, 09 Dec 2020 17:10:23 GMT

I didn't actually apply OpenDNS to the DNS settings as the single IP address field kind of fazed me (I've always seen primary and secondary fields) so as I have never changed the DNS settings on this router before and I am planning how I might to migrate back to the Netgear, I decided to leave it so it is (I guess) using Plusnet's DNS.

No, download is pretty much what ADSL was - maybe I'm getting a 1-2 Mbps bump (according to Speedtest) but it hasn't made a dramatic difference to my life. As mentioned earlier, I live in a remote area but I'm only about half a mile from the exchange. I don't think BT are particularly motivated to improve things, especially as homes about five miles away had 14.4k dialup speeds up until a year or so ago - seriously, a friend of mine couldn't check his e-mail without his girlfriend complaining that eBay was 'down'.

I don't have a static IP per se, in that it isn't supposed to be but I have only had two different IP addresses in the past year or so. I had assumed that a static IP had been imposed as I had tried to force a change a while back by reconnecting (to circumvent an IP download restriction) and couldn't shake it off but about two months ago it changed and has stayed the same since.

I have enclosed a screenshot of the xDSL stats, if you mean the Broadband tab of the member centre on the JLBB website, it doesn't give that information.

I've also added a snippet for an earlier poster who berated me for bringing my JLBB problem to a Plusnet forum. I've been with JLBB and Plusnet alternately for about ten years, I have switched a few times when my contract has ended because the monthly fee went up and I could get a substantial new customer reduction. Stupid, I know but they are not my rules. I was about to switch back to Plusnet when my contract ended and the cost went up without warning (my contract missed the new legal requirement to inform by about a month). Anyway, JLBB offered me the new fibre contract to retain me. [sarcasm]The Zyxel router is my loyalty reward.[/sarcasm]

Re: Zyxel VMG3925 WiFi problems with new devices

MisterW — Wed, 09 Dec 2020 18:37:10 GMT

I didn't actually apply OpenDNS to the DNS settings as the single IP address field kind of fazed me (I've always seen primary and secondary fields)

you must be in the wrong place then, there is primary & secondary. You need to be in Network settings-》broadband , select the vdsl link and click edit. You should see the dns config

Of course doh! Jlbb don't have current line speed or staticbip's

The dsl stats don't show the data rates i was looking for , they're a bit further down

As regards jl and the forums, then yes, the plusnet staff who monitor are not able to provide support for jl problems. Others on here who like me are customers will try and help if we can but we obviously have no access to accounts and so can't provide formal support