Problems with your internet connection could be caused by other people, such as neighbours, using your Wi-Fi. They could be downloading big files, streaming movies and even be engaging in illegal activities like swapping pirated software.
I heard a story once of someone who had a printer in their home and it would occasionally print out pages and pages of documents or web pages and other things.
With a bit of detective work, it turned out that that a neighbour was unknowingly connecting to the person’s network and when they tried to print anything, it would print on the wrong printer because they were on the wrong network. When nothing came out of their own printer, they would try printing again and again.
People could be stealing your network bandwidth causing your computer to run slowly when accessing the internet.
If people are connecting to your network, they also have access to your computer and other devices, with security implications.
Having a password on your Wi-Fi network is a huge help and it should stop most people from connecting and using it.
Of course, it needs to have a password that is hard to guess and using the name of your dog, your favourite sports team, or common ones like 123456 and ‘password’, is a really bad idea.
Even if you have a good password, how many times have you invited people into your home and they have asked you what the password is so they can get online to do something?
Visitors with mobile phones often want to connect to your Wi-Fi to check their email, search for something on the web, and so on. You given them your password without thinking.
Computers, phones and tablets remember network connections and will automatically connect the next time they encounter them.
So even if your neighbours don’t pass on your password to others, their phone or laptop they brought round for you to look at, might continue to connect to your network.
Some routers have really powerful transmitters and it is surprising how far the signal travels.
Change your password occasionally to stop people automatically connecting.
Find the router IP address
There are ways to see what devices are connected to a network and it can be useful to check from time to time, just to make sure that no-one else is using it.
Routers connect computers, phones, tablets and other devices to the network and to the internet. They record what devices are connected and if you know how to access this information, you can check that only your computers and devices are connected.
To access a router you need to enter its IP address into a web browser. What is the address though? There is a way to find out.
Press Windows+R and enter cmd to open a command prompt window and type ipconfig.
Among the information displayed is Default Gateway and this is the IP address of your router. Type those four numbers into a web browser to go to the router’s settings.
Check the devices
On my router’s home page is a list of devices connected to the network. Your router will have this information too, although it may be buried among the settings. You might have to dig around to find it.
To make matters harder, you might need to enter a password to gain access to the router settings and information. This might be written on a label on the back or base of the router. It might be in the router manual, or somewhere else.
I can’t help with the password. Routers have a default password and if you have never changed the default you might find it listed at the Router Passwords website.
Look at the list of devices and see if any look suspicious. The names are not always obvious and this makes it difficult.
Something like android-ede7e6atabz means little, but you have one Android phone and one Android device listed then obviously that’s it.
It would be suspicious if you had one Android phone, but three Android devices listed, or computer names that don’t look familiar.
Set a password
Somewhere in the settings, it is different for each router, so I can’t say where, is the Wi-Fi security. You should choose WPA and enter a password to prevent other people from accessing your network.
Use a network scanner
There are utilities that will scan the network for devices and list them so you can see what is connected. There are some powerful network tools and some expensive ones too, but Wireless Network Watcher is free and works OK. An alternative is Colasoft MAC Scanner.
Where possible, these tools display the device name and the company. As before, it is not always obvious what a device is. The ASUSTek COMPUTER INC in the screenshot above is a Google Nexus 7 Android tablet. It’s made by ASUS.
The SAMSUNG ELECTRO-MECH... is a Samsung Galaxy S6 phone. You have to think what devices might match which device in the list.
Look for anything that cannot be matched with a device you own.