What Is an IP Address? IPv4, IPv6, and Public vs Private
Understand IP addresses — what they are, IPv4 vs IPv6, public vs private, and how to find yours.
What Is an IP Address?
An IP (Internet Protocol) address is a unique identifier assigned to every device connected to a network. Like a postal address for your house, an IP address allows data to be routed to the correct device on the internet.
IPv4 vs IPv6
IPv4 (most common): Four groups of numbers 0-255 separated by dots. Example: 192.168.1.1 or 203.197.36.30.
Total possible IPv4 addresses: ~4.3 billion. The internet has run out of IPv4 addresses — every possible address is now allocated.
IPv6: Eight groups of four hexadecimal digits separated by colons. Example: 2001:0db8:85a3:0000:0000:8a2e:0370:7334
Total possible IPv6 addresses: 340 undecillion — enough for every grain of sand on Earth to have 100 trillion addresses. IPv6 solves the address exhaustion problem permanently.
Public vs Private IP Addresses
Public IP: Your address on the internet. Visible to every website you visit. Assigned by your ISP. Usually one per household/office (your router's IP).
Private IP: Used within your local network (home or office WiFi). Not visible on the internet. Your router translates between public and private IPs using NAT (Network Address Translation).
Common private IP ranges: 192.168.x.x (home routers), 10.x.x.x (corporate networks), 172.16.x.x-172.31.x.x
Finding Your IP Address
Your public IP: Search "what is my IP" on Google, or use Lazyblink IP Lookup.
Your private IP on Windows: Run ipconfig in Command Prompt.
Your private IP on Mac/Linux: Run ifconfig or ip addr in Terminal.
Your private IP on phone: Settings > WiFi > tap connected network > IP address.
Static vs Dynamic IP
Dynamic IP: Most home users have a dynamic IP — it changes periodically when you reconnect or restart your router.
Static IP: A fixed IP that never changes. Required for hosting websites, running servers, or remote access without dynamic DNS. ISPs charge extra for static IPs.
Frequently asked questions
How do I find my IP address?
Your public IP: search "what is my IP" on Google or use Lazyblink IP Lookup. Your private (local network) IP: Windows — run ipconfig in Command Prompt. Mac/Linux — run ifconfig in Terminal.
Why does my IP address change?
Most internet users have dynamic IP addresses that change periodically. Your ISP assigns a new IP from their pool when your router reconnects or at set intervals. A static IP (fixed, never changes) costs extra from ISPs.
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