How to set up a fall-back internet connection when the primary one fails?

RavenLunatic

RavenLunatic

RavenLunatic

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My VM broadband went down last week, and it got me thinking about setting up a backup so all my IOT devices and computers could still operate. My thoughts were to make my phone a mobile hotspot setting the SSID and Password the same as my routers WIFI security settings. Would my computers and IOT automatically jump on to the phones Internet connection if the routers one was unable to connect to the Internet? I am thinking it would act like a bridge connection, but I don’t know enough about networking to the sure. What issues would this cause?
 
That wouldn't work, wireless clients typically roam to the strongest WiFi signal, not the one where an internet connection is working.

Ideally you want a router that allows multiple internet connections (eg dual WAN) and supports failover, but I don't think you can connect your phone as an internet connection with these, you most likely need a compatible 4G/5G modem with its own SIM card for that.
 
In theory, if there are 2 WiFi networks having same credentials then its more likely that your devices would connect with the one having the strongest signal regardless if the internet is accessible or not from there. So you'd have to turn off the non-internet WiFi network to force move all devices to the internet WiFi network.

Regarding the option of mobile hotspot, I'd say it might be suitable for some browsing, email or streaming on probably 1/2 devices. But anything higher than that it's very likely to struggle a lot because the hardware (i.e. mobile hotspot in phones and usual 4G dongles) isn't similar grade like dedicated routers and doesn't have their reach. Still you could give this option a go and see how it works out for you.

If you're unsatisfied then you could go for a dedicated 4g/5g sim router, which should give you the connectivity and WiFi reach like your existing VM router. There may be PAYG options here as well so you'll only pay as you need when the internet goes out on the VM router.

Though keep in mind that if you keep the WiFi credentials same on 2 routers, the above issue of strong signal/WiFi hopping would still surface if both routers are powered on at the same time. The best way to get round this would be to keep the WiFi router separate from the ISP router.

The way this would work is that you get a dedicated WiFi router and turn off the WiFi on your existing ISP router. This WiFi router would then connect with single cable to the ISP router (giving it internet access) and in-turn all your devices would connect to this one WiFi network. So now if the internet goes out, you can simply switch the backend cable of the WiFi router from the VM router to the 4G/5G router instead and all your devices get internet connected without WiFi hopping or having limited connectivity.
 
Fundamentally - as @jokerguv explained above, you need something that will automatically failover to 4G.

So something like a TP-Link AC1200 or MR6400 have a setting where they default to the wired WAN port and then fail over automatically to the 4G if the wired WAN goes off.

You would put your VM router in modem mode then plug the 4G router into that and it would work exactly as you wanted. If you put it on a UPS it would even work if you had a power cut. For a while anyway!
 
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Thanks everyone for your input. My aim is to be just able to browse the web, get e-mails, and for Alexa to control the lighting in my flat. I have looked for a router with a SIM card slot but none of them are capable of 2.5Gb ethernet which I will need. I did find ASUS ROG Rapture GT-AX6000 which claims to have a tethering option for 4G and 5G in the specs which when I think about it is exactly what I am trying to do. There is no mention of a tethering function in the manual.
 
RavenLunatic said:
Thanks everyone for your input. My aim is to be just able to browse the web, get e-mails, and for Alexa to control the lighting in my flat. I have looked for a router with a SIM card slot but none of them are capable of 2.5Gb ethernet which I will need. I did find ASUS ROG Rapture GT-AX6000 which claims to have a tethering option for 4G and 5G in the specs which when I think about it is exactly what I am trying to do. There is no mention of a tethering function in the manual.
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GL.INet MT-6000 will accept a 4G/5G USB stick in its USB port and fail-over to that. Or something like a UniFi Cloud Gateway Ultra Max with the LTE Pro 4G failover but that’s been out if stock for months now. There definitely are options out there.
 
My old Asus XT12's had dual wan with fallback. It worked but was clunky at best. I had two Zyxel 5G Routers attached and would fail between the two. Only issue is the lag between it going down, switching over and then being usable. About 30-60s. Then if you do use an automatic failback, you have to go through that pain again. So I sometimes left failing back as a manual step to avoid flip flopping around. Sometimes it wouldn't automatically do it and I'd have to force it to fail over. So yeah. Not the best experience with that.
 
As people have said above, you need a router that supports failover, a usb 3g dongle and a separate data sim. I've set this up on a Draytek previously and it works quite well but can be a bit sensitive.
 
how many times has your VM broadband gone down for you? if its a lot then yep go for the dual WAN setup but if once in blue moon, its a a lot of expense for a few hours downtime which doesn't really happen often and the kit in place for it will get old very quick.

just my 2p worth :)
 
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Yer I use a UDM with a backup of a 5G router as I work from home, the cost of the contract makes it cheaper then going into the office if the connection goes down and the UDM handles the fail over automagically and messages my phone when it fails over, UDM isnt cheap though.

Stelly
 
I would say I the VM connection usually dies two or three times a year lasting from a day to a month. Last year my VM connection had a serious packet loss problem which took a month to fix which meant no online gaming was possible. I didn’t qualify for automatic compensation as it was not 100% packet loss. I did find out that the tethering function of the ASUS ROG Rapture GT-AX6000 requires a 4G or 5G phone to be plugged into the USB port. I was hopping it would do it wirelessly so I could use my phone at the same time.

For an extra £15 a month I can get unlimited data plan from o2 for my phone and use that as my fall-back. Or I can pay £30 a month for a second internet connection which would probably outperform my mobile phone hotspot by quite a lot.
 
Definitely a router with automatic failover is the way to go. As well as the few off-the-shelf options mentioned you can make your own appliance with 2.5G ports and *sense. I've had this working for years firstly between VDSL and LTE and these days between VM and VDSL. You can set how quickly it fails over based on each interface not responding to x amount of packet loss to the internet. No need to mess around with your WiFI and network once setup. But you have to consider the cost. When I had LTE as failover I couldn't get away with just casual browsing when it was out for hours (and on the odd occasion a car knocked down a telegraph pole, days) so quickly chewed through the data allowance on PAYG. I ended up having a small ongoing subscription that in the event of failover I could 'top up' with unlimited data for a month which would always see me through.

You have to think whether the outlay is worth it for you or if it is so infrequent you could just muddle through tethered to your phone for a little bit and no IOT working.
 
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I hadn’t considered building my own router and WIFI Access point. One of those mini pc’s serve the home review would be quite interesting to play around with. I fear it would be a rabbit hole and I would end up spending £££ on something way overpowered for what I need. I agree that I need a router with failover to do this properly. I’m now not sure my phone will be able to handle 19 WIFI connections at the same time all be it most are smart plugs or lights.
 
You can get a quad NIC N100 based mini PC for less than £200 and the OS is free. Will sip power and route at Gbps no problem. Separating your WiFi from your router I always think is a good idea if you’re vaguely tech minded. Let’s you upgrade/migrate kit over time only where required and means you have the most fit-for-purpose solution for each part of your network. Fun too but obviously a steeper learning curve than just buying off-the-shelf and nothing but community based support normally.
 
BigT said:
You can get a quad NIC N100 based mini PC for less than £200 and the OS is free. Will sip power and route at Gbps no problem. Separating your WiFi from your router I always think is a good idea if you’re vaguely tech minded. Let’s you upgrade/migrate kit over time only where required and means you have the most fit-for-purpose solution for each part of your network. Fun too but obviously a steeper learning curve than just buying off-the-shelf and nothing but community based support normally.
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And just think, in 5+ years, it'll break even vs buying a sub £50 ex corp. desktop... more like 6-7 since power prices dropped/continue to drop.
 
Switch to another ISP? I had similar sounding issues with Virgin that were due to oversubscribed local infrastructure. After 18 months of poor service I got a £12 cheque. Not sure if I even bothered cashing it!

Dual connections for home is probably only a route I’d take if I was doing essential stuff that cost £££ if it went down. Otherwise for personal things it’s a bit of a sledgehammer to crack a nut. The service you are getting is simply unacceptable so I’d start there.

Why do your smart devices not work via LAN if the WAN is down? Seems odd. Obviously browsing the internet is another thing but if you phone has access that’s something. I wouldn’t put it up with it for weeks though, again thats a pretty serious issue with your ISP.
 
I am stuck with VM for another 12 months and I have only recently been given the green light for Openreach FTTP. I am kind of stuck in the Alexa ecosystem, if it cannot call home every time you give it a command nothing works. There must be 4 or 5 different apps on my phone to control all the IOT stuff and it is so much easier just to let Alexa deal with it.
 
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