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What Is an IP Address? How to Find Your IP What Is DNS? What Is a VPN? What Is SSL? What Is WHOIS? What Is a MAC Address? What Is an ASN? What Is a Subnet? What Is a Private IP? IPv4 vs IPv6 FAQ Blog All Tools About Contact
FAQ

Frequently asked questions: 18 short answers about IP addresses, DNS and networks

These are the questions people send us most often. Each answer is a few sentences in plain English, with a link to the longer article when you want the detail.

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IP Address Basics (5)

The numbers every device gets, and how to read them.

What is an IP address?
A unique numerical label assigned to every device on a network. IPv4 uses 32-bit addresses (e.g. 192.168.1.1), IPv6 uses 128-bit.
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What is the difference between IPv4 and IPv6?
IPv4: 4.3 billion addresses, dotted decimal. IPv6: virtually unlimited, hexadecimal colons. IPv6 was created because IPv4 ran out.
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How do I find my IP address?
Public IP: use our tool or Google "what is my ip". Local IP: run ipconfig (Windows) or ifconfig (Mac/Linux). From the terminal you can also run curl ipwhois.net/ip to get your public IP as plain text.
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What is a private IP address?
Reserved ranges (10.x, 172.16-31.x, 192.168.x) used inside local networks. Not routable on the public internet.
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What is a subnet?
A logical subdivision of an IP network. Subnet masks (e.g. /24) split addresses into network and host portions.
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DNS & Domains (3)

How a name turns into an address, and why changes take time to show up.

What is DNS?
The internet's phone book that translates domain names (google.com) into IP addresses (142.250.80.46) so computers can communicate.
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What is DNS propagation?
The time it takes for DNS changes to spread worldwide. Can take minutes to 48 hours depending on TTL values.
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What is WHOIS?
A protocol that reveals domain registration info: registrant, registrar, expiry dates, nameservers. Privacy protection can hide details.
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Security & Privacy (4)

VPNs, certificates, leaks and blacklists in plain words.

What is a VPN?
Encrypts your traffic and routes it through another server, hiding your real IP and preventing ISP tracking.
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What is an SSL certificate?
Encrypts the connection between browser and website. Sites with SSL show https:// and a padlock icon.
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What is a DNS leak?
When DNS queries bypass your VPN and go through your ISP, exposing which sites you visit.
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What is an IP blacklist?
A database of IPs flagged for spam or malware. Being listed can block your emails. We check 40+ lists.
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Routers & Networks (6)

Your router, your home network and the addresses on it.

What is 192.168.1.1?
The most common default router admin IP. Type it in your browser to access Wi-Fi settings, security, and more.
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What is a default gateway?
Your router's IP address that connects your local network to the internet.
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What is NAT?
Lets multiple devices share one public IP. Your router translates between private (192.168.x) and public addresses.
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What is port forwarding?
Directs incoming traffic on a specific port to a device on your network. Used for game servers, cameras, etc.
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What is a MAC address?
A permanent hardware identifier (e.g. 00:1A:2B:3C:4D:5E) assigned to every network card. First 3 bytes identify the vendor.
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What is an ASN?
A unique number identifying a network operator (ISP, cloud provider). Google is AS15169, Cloudflare is AS13335.
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