What Is an IP Address and How It Works

What is an IP address

An IP address, or Internet Protocol address, is a unique numerical identifier assigned to every device connected to the internet or a local network. Just like your home address allows the postman to deliver a letter to the right location, an IP address allows data to find its way from source to destination on the internet. Every computer, phone, tablet, server, router, and any other device that communicates on a network has its own IP address.

When you type a site address into a browser, your computer first contacts a DNS server to translate the domain name into an IP address. Then your browser sends an HTTP request to that IP address, and the server at that address responds with the requested web page. This entire process happens in milliseconds and the user doesn't notice it at all, but without IP addresses the internet as we know it could not function.

IPv4 addresses

Format and structure

IPv4 is the fourth version of the Internet Protocol and the most widespread IP address format, used since 1983. An IPv4 address consists of 32 bits divided into 4 octets separated by dots. Each octet can have a value from 0 to 255, giving a format like 192.168.1.1 or 46.224.157.36. The total number of possible IPv4 addresses is about 4.3 billion, which sounded like a huge number in the 1980s but turned out to be insufficient with the explosive growth of the internet and the number of connected devices.

IPv4 address classes

IPv4 addresses are divided into classes A through E. Class A covers the range 1.0.0.0 to 126.255.255.255 and is intended for large networks with millions of devices. Class B covers 128.0.0.0 to 191.255.255.255 for medium-sized networks. Class C covers 192.0.0.0 to 223.255.255.255 for small networks. Classes D and E are reserved for multicast and experimental use. In practice today CIDR notation is used instead of classes, allowing more flexible address allocation.

Private IP addresses

Specific IPv4 address ranges are reserved for private use within local networks and are not routed on the internet. The 10.0.0.0 to 10.255.255.255 range is the Class A private range with about 16 million addresses. The 172.16.0.0 to 172.31.255.255 range is the Class B private range with about a million addresses. The 192.168.0.0 to 192.168.255.255 range is the Class C private range with 65 thousand addresses and is most commonly used in home networks. Your router uses private addresses for devices in the home network, and the NAT protocol translates private addresses into a single public IP address for communication with the internet.

IPv6 addresses

Why IPv6 is needed

With the growth in the number of devices connected to the internet, IPv4 addresses are practically exhausted. IANA allocated the last block of IPv4 addresses in 2011, and regional registries gradually depleted their stocks. With an estimated over 30 billion connected devices by 2030, IPv6 is essential for the future of the internet. IPv6 is not just a larger version of IPv4 but also brings improvements in security, routing efficiency, and support for mobile devices.

IPv6 format

An IPv6 address consists of 128 bits providing about 340 undecillion possible addresses, enough to assign a million addresses to every atom on the Earth's surface. The format is eight groups of four hexadecimal characters separated by colons, such as 2001:0db8:85a3:0000:0000:8a2e:0370:7334. Leading zeros in each group can be omitted, and consecutive groups of zeros can be replaced with two colons, so the address above becomes 2001:db8:85a3::8a2e:370:7334.

IPv6 advantages

Besides the enormous address space, IPv6 brings several important advantages. IPsec encryption is built into the protocol, while in IPv4 it's optional. Auto-configuration enables devices to automatically configure their IP address without a DHCP server. NAT elimination means every device can have a global address, simplifying peer-to-peer communication and eliminating port issues. A simplified header speeds up routing because routers don't need to fragment packets.

Static and dynamic IP addresses

Dynamic IP addresses

Most internet users have a dynamic IP address that their internet provider assigns automatically via the DHCP protocol. A dynamic address can change every time the router is restarted or when the lease time expires, which is typically 24 hours. Internet providers use dynamic addresses because they more efficiently use the limited pool of IPv4 addresses — not all users need an active address at every moment. For the average internet user, a dynamic address is quite sufficient for everyday browsing, streaming, and email.

Static IP addresses

A static IP address doesn't change and remains permanently assigned to the device. Static addresses are essential for web servers because DNS must know the exact server address to properly route traffic, for mail servers because email server reputation is tied to the IP address, for VPN servers because clients must know the exact address to connect, and for remote access devices, cameras, and IoT devices that must be reachable from outside. Static addresses are more expensive than dynamic ones because the provider must permanently reserve the address for you.

Shared and dedicated IP addresses for hosting

Shared IP address

On shared hosting, multiple sites share the same IP address. The web server uses the Host header in the HTTP request to determine which site to serve based on the domain name. This is economical and functional for most sites. Advantages include lower cost because IP address expense is shared among all users, simple management because the hosting provider handles configuration, and fully functional hosting for standard sites. At BeoHosting, our shared hosting packages use shared IP addresses with optimized servers for excellent performance.

Dedicated IP address

A dedicated IP address is exclusively yours and no other site uses it. Advantages of a dedicated IP include independence from other sites' reputation — if another site on a shared IP gets flagged as spam, that won't affect yours; the ability to access the site directly via IP without a domain; required for some SSL configurations, although SNI technology has made this less relevant; and better control over email reputation. A dedicated IP is recommended for high-traffic sites, email servers, and business applications. For top-tier performance, consider a dedicated server with a dedicated IP address. For top-tier performance, consider a dedicated server with a fixed IP address.

IP geolocation

How it works

IP geolocation is the technique of determining a device's geographic location based on its IP address. Registries like RIPE NCC for Europe maintain information about which organizations have been allocated which IP address blocks. Commercial databases like MaxMind GeoIP and IP2Location combine this data with additional sources to provide city-level accuracy in about 80 percent of cases. Geolocation is used to display localized content, geographic access restrictions, fraud detection, and ad customization.

Geolocation limitations

IP geolocation isn't always accurate because VPN and proxy servers display the server's location, not the user's; mobile users can have an IP address from a different city or country; corporate networks route all traffic through a central exit that may be in another city; and satellite internet providers can have exit points far from the user. Never rely solely on IP geolocation for critical decisions like access control or legal compliance.

IP address security and privacy

DDoS attacks

If an attacker learns your IP address, they can launch a DDoS attack that floods your server with massive traffic, making it unreachable. Protection includes using Cloudflare CDN, which hides the server's real IP address; firewall rules that block suspicious traffic; rate limiting that restricts requests per IP address; and DDoS protection at the hosting provider level. At BeoHosting, we provide DDoS protection on all hosting packages.

Privacy

Your IP address can reveal your approximate location, internet provider, and sometimes even your identity if the provider keeps logs. To protect privacy you can use a VPN that masks your real IP address, the Tor network for anonymous browsing, or proxy servers as intermediaries. GDPR treats IP address as personal data, meaning sites collecting IP addresses must have a legal basis for processing and inform users about it in their privacy policy.

Conclusion

An IP address is a fundamental internet concept that enables communication between devices around the world. IPv4 with 4.3 billion addresses is slowly being replaced by IPv6 with a practically unlimited address space. Static addresses are essential for servers, and dynamic ones are sufficient for everyday users. A shared IP address is economical for most sites, while a dedicated one provides additional control and independence. At BeoHosting, we offer both shared and dedicated IP addresses with DDoS protection and optimized servers for reliable hosting of your site.