IP addresses1 min read
What is NAT? How every device at home shares one IP address
How network address translation works, why port forwarding is needed, how it relates to CGNAT, and why IPv6 doesn't need NAT.
Blog
Practical explanations of how the internet actually works.
- IP addresses1 min read
What is a subnet mask?
Why 255.255.255.0 and /24 are the same thing, how a mask separates network from host, and what wildcard masks are.
- Privacy and security1 min read
What is a proxy, and how is it different from a VPN?
What a proxy server does, HTTP and SOCKS proxies, reverse proxies and CDNs, residential proxies, and the difference from a VPN.
- Routing2 min read
What is an ISP (internet service provider)?
What your provider actually does, where it gets IP addresses, why a lookup may show another name than the brand you pay, and what it can see.
- Privacy and security2 min read
Can someone find me from my IP address?
What an IP address really says about where you are, who can link it to you, and why 'IP tracing' in films is misleading.
- DNS1 min read
What is DNS? The internet's phone book
How names become IP addresses, what a DNS server does, and what changing your DNS does and does not change.
- IP addresses1 min read
How to find your public IP address
The fastest way, and how to find both your public and your private address on Windows, macOS, iPhone, Android and your router.
- IP addresses1 min read
Static vs dynamic IP: the difference, and which one you need
Why dynamic addresses change, what a static IP is good for, where CGNAT comes in and whether a home user really needs a fixed address.
- Privacy and security1 min read
How to change your IP address
Restarting the router, switching to mobile data, a VPN or a fixed IP: what each one changes, and what it doesn't.
- DNS2 min read
How does DNS work?
From typing a name to getting an address: resolvers, root servers, TLDs, caching and TTLs, in plain language.
- Privacy and security2 min read
What is CGNAT (carrier-grade NAT)?
Why your provider may be sharing one public IPv4 address with hundreds of customers, how to tell, and what it breaks.
- IP addresses2 min read
Why does my IP address change?
Dynamic leases, router restarts, mobile networks and IPv6 privacy addresses: the everyday reasons your IP isn't constant.