Internet Protocol (IP)
The Internet Protocol (IP) is a set of rules that govern how data is sent from one computer to another on the internet or a local network. It serves as the primary communication protocol in the Internet layer of the Internet Protocol Suite, also known as TCP/IP.
History
- ARPANET, the precursor to the Internet, began to use a protocol named NCP (Network Control Program) in 1970, which was later replaced by TCP/IP in 1983.
- The initial version of IP, IPv4, was developed in the 1970s by Vint Cerf and Robert Kahn. It was formally defined in RFC 791 in 1981.
- As the Internet grew, the limitations of IPv4, particularly the address space, became evident, leading to the development of IPv6 in the 1990s. IPv6 was standardized in RFC 2460 in 1998.
Functionality
IP provides:
- Addressing: Each device on a network has an IP address, which is unique within its scope. IPv4 uses 32-bit addresses, while IPv6 uses 128-bit addresses to provide more address space.
- Packetization: Data is broken down into packets, each with headers that contain source and destination addresses, and other control information.
- Routing: IP packets are forwarded from one router to another until they reach their destination. This is managed by routing protocols like BGP or OSPF.
- Fragmentation: If a packet is too large for a network segment, it can be split into smaller pieces (fragments), which are reassembled at the destination.
Versions
- IPv4: Uses a 32-bit address format, resulting in about 4.3 billion unique addresses. Features like NAT (Network Address Translation) were introduced to conserve address space.
- IPv6: Introduced to overcome the address space limitations of IPv4. It uses a 128-bit address format, allowing for approximately 340 undecillion unique addresses. IPv6 also simplifies packet processing, improves routing efficiency, and adds security features.
Key Features
- Connectionless: IP does not establish a connection before sending data; it's a "best effort" protocol, meaning there's no guarantee of delivery.
- Datagram Service: Data is sent in packets, called datagrams, which can take different routes to reach the same destination.
- IP Header: Contains critical information like version, header length, type of service, total length, identification, flags, fragment offset, time to live (TTL), protocol, header checksum, source IP address, and destination IP address.
Security
IP itself does not provide security features; however:
- IPv6 includes IPsec for authentication and encryption at the network layer.
- Additional protocols like TLS or VPN are used to secure data transmission over IP networks.
External Links