Networks

I have learned  the hard way how to do this, and it's not just a question of sticking a couple of cables in and everything else is WiFi. So here is how to get high and reliable Internet speeds to your desktop PC or Mac.
I like to think of it as the IT equivalent of having a bath that fills really quickly.
Thinking holistically, you need decent water pressure coming in to the house, good-sized pipes around the house and a good bath tap.
Fast and reliable Internet only comes in to your house via fibre optic or Co-axial cable, preferably fibre optic. Anything that involves copper phone lines is a complete waste of time.
If you only have copper lines then equip your house with the internal bits you need (see below) and when fibre becomes available your bath will fill quickly.
Don’t be bamboozled by anyone selling “fibre to the cabinet” (UK only): this is snake oil.

From the router (the box on the wall) you need Ethernet cables.
Cat5e will do you, this is good for as fast as you’ll need for a good long while yet.
If you’re wiring a new house, use Cat6. It’s a bit more expensive but will support faster speeds (but only when used with faster kit). Don’t be fooled in to paying silly money for Cat6a/7/8 cable, it goes no faster and is a waste of money.

In an ideal world you would run cables from the router to every room in the house plus any outside areas you use, and you definitely need cables to any desktop computers, TVs, audio systems and networked printers, and especially to WiFi base units (see below). No, you can't daisy-chain them.

When building a new house this is relatively straightforward (and few builders are dumb enough now not to do it. That said, I visited a house a few weeks ago that had just been re-modelled and they’d put no data cables in at all, but this was in rural France…) but retrofitting existing houses is tricky and can be expensive and messy.
Here’s the compromise: WiFi doesn’t go through brick, stone or concrete walls.
It does however go through plasterboard (provided it is not foil-backed) and wood.
So generally it does go through ceilings.
Your house consists of a series of "WiFi" boxes, often containing two floors, within which a single WiFi unit will provide fast and reliable WiFi.
Companies will try to sell you mesh radio, extenders, Ethernet over mains power, all manner of snake oil kit.
None of them work reliably.
Over the years we tested all of them, they all fail in different and imaginative ways, but they all fail.

So cables it is: but there are too many cables for the ports on my router?
You need an Ethernet switch. They come in 4,5,8,16,24 and 48 port and they are basically multi-way adapters for Ethernet cables.
Buy one appropriate to the number of cables you have plus the router and a few spares.
Don’t buy “Fast Ethernet”, you need “Gigabit”.

What do I put on the end of the cables?
Anything with an Ethernet plug: PC’s, printers, NAS boxes, WiFi units, Sky Q boxes, TVs and Sonos devices.
Don’t have WiFi and cable connections to the same device.

Sky Q boxes need extra attention: you need to manually disable each box’s WiFi for them to work. This is very important.

But I want WiFi?
Yes, WiFi is great, we love WiFi, and now you’ve offloaded the majority of your Internet traffic to the cables you’ve freed lots of WiFi bandwidth for your iPads, iPhones, Kindles and WiFi-only printers.
Now get good quality dual-band WiFi units and place one in each WiFi “box” (see above).
Ubiquiti units are the best but they require specialised Ethernet switches, a dedicated controller unit and a fair bit of knowledge.

Most houses don’t need that expense, so a number of TP-Link Archer 1200s or similar will do the trick.

You’ll need dual-band WiFi because the old, 2.4GHz 802.11b standard is only good for about 80-90Mbit, whereas the newer 5GHz 802.11AC and 802.11AX WiFi6 standards will go to about 600Mbit.
On each WiFi unit you need to turn off the slow old 2.4GHz 802.11b WiFi so only the newer 5GHz WiFi is running.
You must set all the WiFi units to exactly the same WiFi name (UpperCase and lowercase are different), password and encryption type (use at least WPA2 or WPA3 or you will get "weak encryption" messages when you connect your iPhone or iPad).
Then you need to manually set the WiFi channels to be different from each other and the bandwidth to 80MHz.

WiFi clients such as laptops and phones will see a number of WiFi units on the same network as they move through the house; some stronger and some weaker, and will connect to the strongest unit for the fastest connection but only if the units are on different channels.
So at any location in the house it must only see 1 WiFi unit on each channel.
It can cope with multiple units on different channels but it can’t cope with multiple units on the same channel.
Also, the AUTO channel settings never work, they just set all the units to channel 36.

Using TP-Link Archer units works well up to about 8 units at which point the management of the settings becomes laborious.
You can install more than 8 but you’ve just got to be very organised.
For larger setups such as commercial premises a unit such as a Ubiquiti Cloud Key and Ubiquiti WiFi units is a better option as you set everything up once on the controller and then the controller programs (“adopts”) each WiFi unit.

Every network needs a private IP range. Your firewall (usually your router) separates you from the Internet and assigns this for you.
You can find out your local IP address by running a command prompt and typing IPCONFIG and pressing Enter. This will also tell your router (or "default gateway") address.

You can find out your public IP address by going to the website www.whatismyip.com.
Your network will be something like 192.168.1.xxx where 192.168.1.1 or 192.168.1.254 is the router. The router will assign a range within that for DHCP devices (computers, phones, tablets, TVs etc) that you can discover by logging in to it. Only addresses between .1 and .254 are valid.
If you have devices that serve (NAS boxes, networked printers, servers, WiFi units they need assigning a static address outside the DHCP range. Sometimes the DHCP range on the router is set to start at .2 and go all the way to .254 so it will need changing to allow static addresses, to something like .10 to .254.
Once you've assigned static addresses to the serving devices you can always find them easily.
DNS Naming NetBIOS stuff