We will start our series on internet privacy with our first topic, VPNs. To correctly understand this technology, you need to know how IP addresses work and how your ISP is tracking all your internet activity. In this chapter, you will learn all those things and find out why it is so important to conceal and hide your IP address.
Using a virtual private network (VPN) is a method to hide your IP address. Let us first explain what that is: An IP address is a numerical label assigned to each device connected to a computer network. As soon as you connect your PC to a network with an Ethernet cable or Wi-Fi or use the internet on a phone, you get a unique IP address.
The most common type of IP addresses is IPv4, the Internet Protocol version 4 address. The more recent IPv6 appeared for the first time in an Internet Draft for the Internet Engineering Task Force (IETF) in 1998, but was only ratified as an Internet Standard in 2017.
The number of IPv4 addresses is limited, so the new standard IPv6 has been developed to support more addresses. IPv6 also offers privacy benefits, due to the built-in authentication and privacy features. IPv6 has some known security issues. When a network is set up for use with IPv4 and then transitions, an IPv6 shadow network can appear and create an entry point for attackers. Another issue is that attackers can use IPv6 packet fragmentation to evade network security controls. Aside from these, it is more secure than IPv4.
IPv4 and IPv6 are incompatible and many devices and protocols, including VPN protocols, do not work with IPv6 yet. IPv6 uses hexadecimal digits.
| Type | Address |
|---|---|
| IPv6 address full Nixon | 2001:0db8:0000:0000:0000:8a2e:0370:7334 |
| IPv6 address simplified | 2001:db8::8a2e:370:7334 |
| IPv4 address | 69.89.31.226 |
Those addresses are based on your internet service provider’s (ISP) network. They can reveal your general location and even identify yourself if you are a customer of a certain ISP. An IP address is needed for internet communication between you and a (website’s) server or you and another computer (P2P). The address is necessary for the world wide web to function.
If IP addresses did not exist, your PC would not know where to send data packets to. It is, however wise to not show your real IP address in some situations.
Since they are necessary, everyone has an IP address, which is why they can be abused to track you. Many web servers automatically record all IP addresses they communicate with. As we have said before, IP addresses are assigned to your by your ISP. That means that these companies know your address at all times and can identify you if requested by law enforcement or in case their servers are hacked. The latter would then enable an attacker to reconstruct your entire activity.
If you ask us, we think that the internet has been implemented the wrong way, right from the beginning. A system where everybody’s PC or phone is clearly identifiable at all times should never have been put in place. Luckily, you have many options to circumvent the tracking and hide your IP address. One of them is using a VPN, which will be the topic of our next article.
These companies know your IP address at all times, but that is unfortunately not the only problem with ISPs. Your ISP can see everything you do online, since they observe every request you make. All your web traffic goes through their data centres and they do not limit themselves to the necessary information, like your IP address and billing information.
Most ISPs lack transparency and you do not know how much data is actually saved in their logs. There lies the problem, since they happily share the data with government authorities and law enforcement upon request, but if their servers get hacked, also with criminals.
Some ISPs, such as Verizon, are worse than others. Verizon Wireless keeps a record of the websites you visits for a year and text messages for 5 days. Virgin Mobile keeps text messages (content) for 3 months and a record of who messages who and the date and time, for 3 months. AT&T Mobility keeps a record of who messages who and the date and time, for 7 years. Yes, 7 YEARS! (source)
Please do your research on your local provider to find one that is less privacy invading than the mentioned providers in the US.
Not only user IP addresses are interesting, servers do also have an IP address. Sometimes, you just want to know who you are dealing with. A server on the world wide web (WWW) cannot conceal its real IP address, since that would make reaching the website impossible. A server’s IP address is registered in the Domain Name System (DNS). The DNS is the system that redirects a request to the yahoo.com Uniform Resource Locator (URL).
If you type yahoo.com into the browser, you will be directed to the right server. That is the server that hosts the Yahoo website. In this process, a DNS server resolves the host name and translates it to the associated public IP address.
In the following, we will show you how to look up a server’s IP address. That can be interesting, because you will sometimes find websites that claim to be from a European country or North America, but then you discovers that their servers are located in a completely different place, e.g. Tonga or Panama.
Just for your information, our website is hosted on a server in Berlin. Our admin is German and most team members are international students in the Netherlands.
Windows
To find out the IP address of any server on Windows, open the command prompt (cmd). Write nslookup and then type in the website, e.g. www.yahoo.com. Hit enter and you get its IP address, e.g. 87.248.98.7 It looks up the IP with a query at the Domain Name System (DNS). Alternatively, you can ping the server with the command “ping yahoo.com”.
Linux
To find out the IP address of any server on Linux, open thencommand prompt (Terminal). Write host or nslookup and then type in the website, e.g. www.yahoo.com. Hit enter and you get its IP address, e.g. 87.248.98.7 It looks up the IP with a query at the Domain Name System (DNS).
macOS
To find out the IP address of any server on macOS, open the command prompt (Terminal). Write nslookup and then type in the website, e.g. www.yahoo.com. Hit enter and you get its IP address, e.g. 87.248.98.7 It looks up the IP with a query at the Domain Name System (DNS).
After you know the IP address, you can find out the geolocation. You can look up a server’s IP address on WhatIsMyIPAddress.com and find out exactly where the machine the IP address points to is located.
For more advanced information gathering, you can get technical details about a server on BrowserSPY, Hacker Target and Pentest Tools.
A guide on general information gathering is provided by the InfoSec Institute. They also have a guide on the Metaspoit pen-testing framework and you can find a hacking introduction on Guru99.