How To Set Up A Home Internet Connection That Almost Never Goes Down

An ISP router. Your one “box” that did everything may soon be replaced with four that do parts of the setup. Photo: author.

Recently, I spent the best part of three weeks attempting to figure out a decisive solution to my intermittent home internet connection.

The rabbit hole proved to be both one of the deepest and most engrossing I have ever plumed down.

It took me back to my early post-Linux days when I first decided to host a web-server off an old laptop, waiting to be called for a job interview while my laptop attempted to load my email over a sluggish home internet connection. That was fun.

I learned about Starlink’s ongoing efforts to bring low earth orbit satellite internet around the globe.

I briefly toyed with the idea of attempting to build my own cellphone tower to improve 4G connectivity before realizing that — as a renter — trying to “unpack” and transport my cellular tower to my next locale would likely have posed a logistical difficulty (also, laws..).

I considered, also, installing a point to point outdoor repeater to beam over fiber-speed connectivity from another part of my neighborhood served by the infrastructure. Before realizing that the ranks of those both crazy enough to want to participate in such an experiment and who lived sufficiently close to me were likely vanishingly thin.

I spent a fascinating few hours dissecting cellular and home internet connectivity in my country. locating transmitter towers on openly available government mapping systems and learning about how the sprawling ranks of virtual mobile network operators (MVNOs) obscured the fact that there are basically only three cellphone infrastructures in my country. (This was to identify the most fruitful cellular connection source, covered later).

I learned about the differences between connection bonding, load balancing, and failover — which are unfortunately lost on some over-enthusiastic YouTubers (the snappy version: if you want to do actual channel bonding between multiple connections, you either need to work with an ISP that will do that for you on their side or provision something like a VPS yourself to separate out the bonded trunk. But if you’re interested, and like open source, check out OpenMPTCProuter. If you’re happy to pay monthly and probably run it on the device level, check out Speedify)

Between the hours of 00:00 and 04:00, for about a week, I worked with the feverish energy of an emergency electricity repair crew. Experimenting with various combinations of hardware and measuring average failover times by the second to try to build a home internet network that would withstand whatever rain, thunder, and the vagaries of local bandwidth demands could throw at it. Waking up every morning to a progressively more glorious connection.

My work is far from done. My iteration is only V1. But I have learned enough to have become slightly maddened by the quest for progressively more reliable internet. And to want to share the first successes.

Rule 1: Never Rely Upon A Single Source Of Connectivity

V1 of my home networking stack in place. Shown: ISP router, load balancer, cellular router. Photo: author.

The first rule for building a highly available home internet network is that you never want to put your faith in any single source of connectivity.

People talk in hushed terms about fiber optic internet — which is currently being deployed around Israel.

But the grizzled folk who’ve been running internet service providers (ISPs) for more years than they can remember and who can often be found dissecting home networking setups for fun on Reddit will be quick to tell you that fast and reliable are not the same thing.

For those wishing to plumb this rabbit hole, the good news is that there is lots of information online about how to build really highly available infrastructure.

The traditional goal standard, for connectivity, is something referred to as “five nines” uptime. That’s uptime of 99.999% — which translates to only about 5 minutes of downtime a year.

Who needs this kind of stuff?

Well think about your local ambulance service for once. If their dispatch system were to go offline because the “internet was down” people would lose their lives.

There are many industries that rely upon really highly available infrastructure of every kind (internet being only type of infrastructure) but that’s the general picture. There are industries who need internet that basically never goes down. Thus there are hardware solutions to meet that use-case.

Rule 2: Never Rely Upon A Single Piece Of Internet-Providing Hardware (For The Truly Dedicated)

Roadworks are common causes of disruption to internet connectivity sources that travel over land (often: DSL)— or under it (fiber optic). Photo by Mabel Amber from Pexels

Recently, I posted in the excellent /r/homenetworking subreddit asking whether near total availability was actually feasible for your average home network tinkerer.

The answer I got back was both discouraging but accurate.

I thought I had defeated the forces that rob internet from routers by provisioning a cellular connection and load balancing that with my ISP line.

Alas, I had made one rookie prepping error: my network design was filled with single points of failure:

  • I only had one router
  • I only had one load balancer
  • I only had one network interface card (NIC) bringing ethernet into my desktop

Now, when you really think through business continuity questions like this you can and will go slightly crazy. So let’s focus instead on just the top-line stuff: the components that — were they to break — really would mean internet was down:

  • The router
  • The load balancer

Technically — because my cellular router is before my load balancer and on separate hardware to anything else — I do have a backup/secondary connection that is independent of hardware.

But that would require shifting to an inferior connection source. The truly dedicated will build alternative standby routes for every single essential piece of hardware — even the card that takes the connection and brings it into their computer.

Implementation: Load Balance Multiple Connections And Setup Failover

Even speedy internet connections can and do commonly fail. Therefore, load balance multiple different connection sources into one local network. Photo: author.

Now that we’ve got those essential caveats out of the way, here’s how to actually make it all work:

Bring your multiple connection sources into a load balancer and set up the most appropriate failover rule for the connectivity you have.

That means that when connectivity A goes down the intervening device on the network — the load balancer in my case — will swap connectivity over to connectivity B.

I also recommend not buying a load balancer with WiFi even though they exist (they also tend to cost more).

I initially thought that I was running too many pieces of hardware on my network before I realized that separating out my network component by component was actually giving me a lot more flexibility than if I had everything running off one device (for instance, once 5G cellular routers become more affordable I can upgrade my 4G setup to that while keeping the rest of the setup intact.)

Putting a WiFi router that can be configured as an access point — or just an access point — after the load balancer will mean that the WiFi network has the built-in failover built into it.

Note: you don’t technically need to use a load balancing router. Particularly because I’m not actually doing any load balancing.

But you will want a multi-WAN (wide area network) router and it’s probably best — because of the way most houses are laid out — to create a WiFi network from a separate piece of hardware.

Multi-WAN wired-only routers do exist. But disproportionately they tend to be marketed under two names:

  • Load balancing routers
  • VPN routers

They also typically tend to be used by businesses or data centers. So expect to pick up something that looks a little less familiar and friendly than what you may have been using to get home internet connectivity for years.

For most brands, you can simply do failover and provisioning backup connectivity sources without using any of the load balancing or VPN features.

Here’s my configuration in my TP-Link TL-R470T+ load balancing router:

Multiple Connection Sources: Which Connections To Choose?

What connection sources should you use?

That depends upon your budget as each one will typically involve a separate subscription fee.

It also depends upon your hardware.

For instance, my load balancer has a maximum of four WAN ports (typically a couple are interchangeable and can be set as LAN or WAN).

That means that I could run 4 WANs into the load balancer and run all my LAN devices off one port using switches.

Where I’m based, data-only cellular plans are cheap.

So combining my ISP connection (VDSL) with a 4G cellular plan actually only adds another $10 per month only my internet bill (not excluding the hardware purchased to set this up).

You could also subscribe to two ISPs. Although I think that cellular adds an additional layer of protection because one infrastructure is primarily over the air — at least up to a point.

You could also do satellite and ISP if you are somewhere rural.

The options are wide.

My thinking: even if I had an incredibly reliable primary line, I would be happy to pay for an affordable second one just to know that I had an always-available backup connection.

The Finishing Touches

  • By the time you’re finished with the setup, you may have a stack of hardware instead of one “box” that formerly did everything. I now have four components on my network: my ISP router (which is just running as a bridge), a cellular router, a load balancer, and a WiFi router (running as an access point). To mitigate against temporary power outages bringing the whole network down, run these off an uninterruptible power supply (UPS).
  • You might — as I did — spend a bit of time playing around with possible configurations and wiring setups.
  • To maximize the effectiveness of the cellular connection — if you’re using one — it should have as good a connection as possible to the cellular network. I recommend buying a cellular router that has external antenna support. This means that you can rig up a rooftop antenna to bring down the best possible connectivity.

To Take Things Really Far …

  • Subscribe to a data plan from each cellular connectivity provider in your area. You may need to put each connection on its own hardware.
  • You could also look into cellular bonding plans, although these typically involve monthly fees. Terradek is dominant in this space.

Some Sketches For Ideas

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Daniel Rosehill

Daniel Rosehill

Daytime: writing for other people. Nighttime: writing for me. Or the other way round. Enjoys: Linux, tech, beer, random things. https://www.danielrosehill.com