What does IP stand for?
IP stands for Internet Protocol. The protocol that addresses and routes packets between networks. In logs and investigations, source and destination IP addresses are key evidence.
IP is the network-layer protocol of the internet. It gives every interface an address and moves packets hop by hop from the source address to the destination address: each router reads the destination and forwards the packet one step closer. IP itself is best effort. It does not guarantee delivery or order, which is the job of TCP above it. Two versions are in use. IPv4 has 32-bit addresses written as four decimal numbers, and IPv6 has 128-bit addresses written in hexadecimal.
IP in practice: an example
A laptop at 192.168.1.20 opens a website. Its packet carries the laptop's address as source and the web server's address as destination. The home router forwards it to the provider, each router on the path forwards it again, and the reply comes back with the two addresses swapped. In a firewall log, those two addresses are what tell an analyst who talked to whom.
What IP is confused with
IP vs TCP: what is the difference?
IP delivers individual packets between addresses and promises nothing more. TCP runs on top of it and adds connections, ordering and retransmission. The name TCP/IP is the pair. What TCP stands for
IP vs MAC address: what is the difference?
An IP address is a logical address used to route between networks, and it changes when a device moves. A MAC address is the hardware address of a network interface and is only used inside the local segment. ARP maps one to the other.
Which exams cover IP?
IP is on the official CompTIA acronym list for all four exams covered here.
- Security+ SY0-801: 2.5 (Threats, Vulnerabilities, and Attacks).
- CySA+ CS0-004: 1.3 (Security Operations).
- Network+ N10-009: 1.0 (Networking Concepts); 2.0 (Network Implementation); 3.0 (Network Operations); 5.0 (Network Troubleshooting).
- A+ 220-1201 and 220-1202: 220-1201 2.0 (Networking); 220-1202 1.0 (Operating Systems); 220-1202 2.0 (Security).
Each number is a CompTIA exam objective and the name in brackets is its domain. The exam puts the term in a scenario; it does not ask you to recite the expansion.
Check yourself: two practice questions
Written by CertSprint for this page. They are not taken from any exam.
1. A PC can reach other devices on its own subnet but nothing beyond it. Its IP address and subnet mask are correct. Which setting should be checked first?
- The default gateway
- The screen resolution
- The printer's MAC address
- The NTP server
Show the answer
A. The default gateway. Traffic for other networks is sent to the default gateway. If that address is missing or wrong, local communication still works and everything remote fails.
2. Which statement about IPv4 and IPv6 addresses is correct?
- IPv4 addresses are 32 bits long and IPv6 addresses are 128 bits long
- IPv4 addresses are 48 bits long and IPv6 addresses are 64 bits long
- Both are 32 bits long
- IPv6 addresses are written as four decimal numbers
Show the answer
A. IPv4 addresses are 32 bits long and IPv6 addresses are 128 bits long. RFC 791 defines 32-bit IPv4 addresses and RFC 8200 defines 128-bit IPv6 addresses. A 48-bit value is a MAC address.
Sources: RFC 791: Internet Protocol; RFC 8200: Internet Protocol, Version 6 (IPv6) Specification; NIST glossary: Internet Protocol. The acronym and its expansion come from CompTIA's official acronym lists, linked from each exam glossary above. The explanation, example and questions are CertSprint's own, checked against these sources on 12 November 2026.