Glossary Term

IP ADDRESS

The numerical address (IPv4 or IPv6) that identifies a server or device on the internet.

Definition

An IP address is a numerical label assigned to every device connected to the internet, used to route traffic to the correct destination. IPv4 addresses use 32 bits and look like 76.76.21.21, four numbers from 0 to 255, giving about 4.3 billion possible combinations. IPv6 addresses use 128 bits and look like 2606:4700:4700::1111, longer, hexadecimal, and designed to solve the IPv4 address shortage with a practically unlimited address space. Every web server has at least one IP, and DNS exists to map human-readable domains to those addresses so visitors never type numbers. In web hosting, the distinction between a shared IP, used by many sites on one server, and a dedicated IP, used only by your site, matters for some legacy SSL workflows that predate SNI, email sender reputation, and a small number of geo-restricted use cases. Most modern hosting setups never require you to touch this distinction directly.

How it works

A web request from a browser carries the destination IP in the IP packet header; the network routes the packet through routers until it reaches the server. The server's reply carries the visitor's IP back. NAT, load balancers and reverse proxies all rewrite IPs along the way.

Why it matters

For most modern web hosting, you do not need to think about IPs at all: DNS handles the mapping. The cases where IP matters are dedicated IP requirements (some legacy SSL, some email-sender setups), abuse handling (a shared-IP blacklist hurts everyone on it), and geo-restricted access.

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Frequently Asked Questions

Do I need a dedicated IP?

Most modern sites do not. Modern SSL uses SNI and works fine on shared IPs. Dedicated IPs help with some legacy SSL setups, email sender reputation, and geo-restricted services.

What is the difference between IPv4 and IPv6?

IPv4 has about 4 billion addresses and is the original protocol; the world ran out. IPv6 has effectively unlimited addresses and is the modern successor. Most production hosts support both.

How much does a dedicated IP cost?

Shared hosts typically charge about USD 2 to 5 a month as an add-on. VPS and cloud providers often assign a dedicated IP by default at no extra charge, since you are not sharing the underlying server with other tenants.

How do I find my server's IP address?

Run a DNS lookup command such as dig or nslookup against your domain, or check your hosting control panel, which usually lists the server IP under domain or DNS settings. Support dashboards for VPS and cloud accounts show it directly.

What breaks if my IP address changes unexpectedly?

DNS records still pointing to the old IP cause downtime until you update the A record, which can take minutes to hours to propagate. Email deliverability can also drop if SPF records reference the old IP, and any external firewall whitelists tied to it stop working.

Related Terms

DNS
The internet's address book that translates domain names into the IP addresses computers use.
A Record
A DNS record that maps a domain (or subdomain) to a specific IPv4 address.
WHOIS
A public lookup that returns ownership and registration details for a domain name.
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