[SOLVED] Second router is taking control of the internet on some devices and breaking things. Help appreciated.

Noki0100

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Feb 28, 2019
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Hi All, I have a problem I can't seem to solve by myself. I have been through all the settings on my network devices I can't seem to find what I am looking for.

Problem:
The gist of my problem is that I have 2 ISP's, Virgin Media and Sky. The Virgin internet is the top package, the Sky is the slowest and cheapest available, therefore a backup to the main internet going down. Problem is that many of my devices, but strangely not all, decide to exclusively connect to the internet through the Sky router when it is available.

I must have a separate WiFi access point downstairs as whoever built my house seems to have made it a Faraday cage at the same time. The Virgin Hub 3.0 is set to modem mode and has no other configuration options. I recently brought an Asus RT-AC66U_B1 to function as the main Router and for more up to date WiFi access than I had previously, it is also the DHCP. I have included a network diagram below for clarity.

As I stated this works for some devices, but not others. My main PC 'GrandSlam' works fine Getting full fat internet no matter what I change. My phone on the other hand (a OnePlus 7 Pro) is using the Sky Router if it is available, but works fine if I completely unplug the Sky Router, and ONLY when it is fully off.

The problem is not limited to WiFi as this also breaks my work Laptop (and I do have admin access so can't dig into it on there) but this happens when wired or WiFi on there.

Other info:
I have the option on the Sky Router to 'Disconnect' the modem and keep WiFi on, which I assumed would be sufficient. It is not, all that does is prevent web access entirely.

I find it strange that even when connected to the main routers wifi it would still use the Sky as the route to the internet are more convoluted than the direct connection it would have from the router it is connected to. I might understand it if was limited to the wifi directly from the Sky Hub.

I also have a PiHole as a DNS Blocker, but that shouldn't be part of this problem, just something to be aware of.

What I am looking into:
Now, I can see an option to have a dual WAN on the Asus Router. However I am not convinced setting it up this way will fix my problem. In addition it would mean running another cable outside my house to make this work in the first place. Is anyone able to confirm whether this would be a fix that will work for me?

Is this even fixable with the consumer grade hardware I have? I'm guessing it might simply be that the Sky Router is designed to be idiot proof and forces itself to work somehow, and the options to change this are not exposed in the basic GUI provided for updating settings.

The only other solution I can think of it to get the Access Point (an old slightly crap one I have, Tp-Link I think) and putting that downstairs. I would prefer to use the Sky though, is it uses a more modern WiFi standard and can act as a fallback if needed (not that it's really important for home use I guess).

Or anything else I can try. Any suggestions appreciated.

Examples:
ConfigurationGrandSlam PC (Ethernet)Android Phone (Wifi)
Sky On and 'Connected' to the webSpeedtest: ~380 MBSSpeedtest: ~1 MBS
Sky On but 'Disconnected' from the webSpeedtest: ~380 MBSBroken, no internet access
Sky Router Powered OffSpeedtest: ~380 MBSSpeedtest: ~380 MBS

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Solution
You have enough network devices, that you should upgrade your network hardware. A dual WAN router to automatically fail over to your backup and a wireless access point rather than a second router.
I am going to bet you are using the same IP address on both routers for the gateway. This will cause random distribution of traffic. Even if you don't I can't see how you expect this to work.

If your main internet would fail how do you expect it to know that and move to the other router.

You are best off using a dual wan router but you could set the main router to say 192.168.1.1 and the second router to 192.168.1.2. You want to be sure you have the DHCP disabled on the second router.

This will require you to manually fail the devices over to the other ip address as the gateway.
 

Noki0100

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Feb 28, 2019
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Thanks for quick responses.

The Asus router is performing as the only DHCP as far as I can tell. It is disabled on the Sky router for sure. I could also switch to using the PiHole for that, but didn't see the point.

The Asus router does have Dual WAN support, but as I said requires a new cable to be run outside the house. Hassle but I am will to do it if this is definately the solution.

As for Gateway, the Sky Hub is showing '2.127.238.77' and the Asus Router is set to 'blank' which in the manual says that means it is referring to itself '192.168.1.2'. I can't find this information exposed on the Virgin Hub when it's in Modem Mode. I will check again in the morning in case I am wrong.

Also the Virgin Hub becomes unreachable when the Sky Hub is powered on. It's on it's default IP for modem mode, '192.168.100.1'.

I will try again tomorrow to look into Gateway settings.

As for the number of devices, I don't always have all of these on all the time. Perhaps 5 or 6 Wifi devices and the same for wired devices at any given moment.
 

Noki0100

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Feb 28, 2019
53
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4,545
As far as I can tell I am not duplicating IP's on my network. Everything is either using the DHCP or I have manually set them to a number and excluded a portion of IP's for that purpose.

Virgin Hub (Modem mode) - 192.168.100.1
Asus Router - 192.168.1.2 (active DHCP server)
Sky Hub - 192.168.1.3
PiHole - 192.168.1.10

DHCP Range 11 - 253

As for setting a gateway on my end devices the Sky Hub doesn't seem to have this option exposed in the UI shown below.

Is being able to set the Gateway required for this to work? I am going to run the required cable shortly and don't want to waste my time (and 8 meters of cable).

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Noki0100

Reputable
Feb 28, 2019
53
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4,545
OK, cable has been run. Existing hole needed some persuasion with a giant drill bit but it's done.

All seems well now, devices that were not working before now do get full speed so thanks everyone for confirming this was the right thing to do.

I do have a minor issue with accessing local machines when connected to the downstairs WiFi (which I havent dug into yet) but otherwise the major problem is dealt with. I was hoping the second port on the Sky Hub would will allow it to route internally, but not the end of the work if it doesn't.

Thanks again.