IP adresa

What is an IP address?

An IP address (Internet Protocol address) is a numerical identifier for a device on a network. Every computer, phone, server, or router connected to the internet has a unique IP address, much like every building has a unique postal address. Without IP addresses the internet could not function — every communication must have a sender and a recipient.

There are two formats:

• IPv4 — the original standard from 1981. Format: 4 numbers from 0–255 separated by dots (192.168.1.1, 8.8.8.8). 4.3 billion addresses — address space is exhausted.
• IPv6 — the newer standard gradually replacing IPv4. Format: 8 groups of hexadecimal numbers (2a01:abc::123). Virtually unlimited address space.

In 2026, IPv6 dual-stack is supported by most internet service providers across the EU.

When it is used

For a business owner, four practical distinctions in IP addresses matter:

Public vs. private

• Public IP — routable from the internet, assigned by the internet service provider. Typically one address for an entire business connection.
• Private IP — used within the company’s local network (LAN). Standard ranges: 10.x.x.x, 172.16–31.x.x, 192.168.x.x.

Static vs. dynamic

• Static IP — permanent, unchanging. Cost: 5–20/month from an ISP. Important for an own server, email server, VPN endpoint, or IP whitelisting in cloud applications.
• Dynamic IP — changes over time. The default for most connections.

IP whitelisting

Many cloud services allow you to restrict access to your company’s IP only. Examples: Microsoft 365 Conditional Access, AWS admin console, ERP admin actions. IP whitelisting is not possible without a static public IP.

IP in the audit log

During a security incident, an IP address is a critical trace. The Modulario audit log records the IP address for every change in the system — an attack from a foreign IP in a country where the company has no employees is an immediate signal.

Related terms

• VPN — a virtual private network; changes your apparent IP address
• SSL — a security protocol independent of IP, but often used in combination
• Hardware — physical devices to which IP addresses are assigned

In Modulario

Modulario supports IP whitelisting at the administrator level — critical functions (data export, structural changes, billing) are accessible only from the company’s IP address. The audit log records the IP address for every action along with geographic location (continent, country) — anomalies are detected quickly.

For a detailed explanation of IP addresses, see the cluster article What is an IP Address and Why Does it Matter and the pillar IT Fundamentals for Business Owners.