VPNs - the good and the bad

[StuartR]

Someone sent me a PM asking about VPNs, so I thought it might be good to summarize some of the issues here.

Why use a VPN?
When you connect to a VPN, all of your internet traffic is encrypted at your end, and then sent to a server somewhere on the internet. This server decrypts the data and sends it on. The end web site returns any response to the VPN server, which encrypts it and sends it to you.

This has a number of benefits.

1. All traffic to and from your device is encrypted. This makes it much safer to use public WiFi in places like hotels and coffee bars.
2. The web site you are communicating with can't see your IP address, it can only see the IP address of the VPN server. This makes it much harder for them to track you and helps to protect your privacy.
3. By picking a VPN server in a particular country your traffic will appear to come from that country. This can help you to get round arbitrary restrictions on who can access what data.
4. Nobody other than the people who provide the VPN server can see what web sites you are accessing. This may help to protect you if you are travelling in a country where they try to restrict your internet access.

What problems can you have when using a VPN?

There are a number of problems that might affect you when using a VPN.

1. Your traffic has to travel over extra hops, so your internet bandwidth will be less than a direct connection
2. It takes time to encrypt and decrypt all the data, so the latency may be increased, further slowing your connection
3. Your VPN server may have stability or throughput limitations, making your connection unstable or unreliable

Given all of this, I tend not to use a VPN when I am at home, connected to the internet via my own router. BUT whenever I am using someone else's router I accept the reduced performance and reliability.


What does it cost?

There are some free VPN services available, but these tend to have very severe performance and reliability issues. So I choose to pay a monthly subscription, which works out at about $70 (US) per year for up to six devices. There are a number of different companies that you can buy VPN services from, so if you're tempted I suggested you take out the shortest subscription they offer to see how well it works for you before committing to a longer contract. Use your favourite internet search engine to look for VPN subscription to see some alternatives.

[John Gray]

Thanks, Stuart - I'd be interested in your further thoughts on whether Windows 10 has done anything to improve the standard "home worker using Microsoft RDP using a VPN to connect into a server or PC at work, with a decent work router like Draytek Vigor 2820 to terminate the VPN".

[HansV]

Thanks for this clear summary, Stuart!

[Rudi]

Great summary and useful reference.

[BobArch2]

Another feature to look for in a VPN is a kill switch. With the kill switch turned on, your Internet connection is severed immediately should the connection to the VPN drop for whatever reason. Without the kill switch, if the VPN connection is dropped, you are exposed in the sense that your access will revert to an address tied to your ISP.

Re-establishing an Internet connection and getting back on with the VPN access is easy enough. At least it is with the VPN that I use.

[BobH]

Great information and very well presented!

Thank you, Stuart!!!

[StuartR]

I agree with your point about the kill switch Bob. My VPN service also includes DNS leak prevention which is another important feature if you are feeling really paranoid.

[StuartR]

John,

The use of VPN to connect to your work network is very different to what I was describing. This is usually done to provide controlled access to your work network for travelling staff, and I haven't researched the tools used for this for some years now.

[Claude]

Great post Stuart, thanks.