Frequently Asked Questions

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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IPv4: 4.3 billion addresses, dotted decimal. IPv6: virtually unlimited, hexadecimal colons. IPv6 was created because IPv4 ran out.
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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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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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A logical subdivision of an IP network. Subnet masks (e.g. /24) split addresses into network and host portions.
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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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The time it takes for DNS changes to spread worldwide. Can take minutes to 48 hours depending on TTL values.
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A protocol that reveals domain registration info: registrant, registrar, expiry dates, nameservers. Privacy protection can hide details.
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Encrypts your traffic and routes it through another server, hiding your real IP and preventing ISP tracking.
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Encrypts the connection between browser and website. Sites with SSL show https:// and a padlock icon.
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When DNS queries bypass your VPN and go through your ISP, exposing which sites you visit.
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A database of IPs flagged for spam or malware. Being listed can block your emails. We check 40+ lists.
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The most common default router admin IP. Type it in your browser to access Wi-Fi settings, security, and more.
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Your router's IP address that connects your local network to the internet.
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Lets multiple devices share one public IP. Your router translates between private (192.168.x) and public addresses.
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Directs incoming traffic on a specific port to a device on your network. Used for game servers, cameras, etc.
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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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A unique number identifying a network operator (ISP, cloud provider). Google is AS15169, Cloudflare is AS13335.
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