TCP can reorder segments that arrive out of order and retransmit missing segments. TCP is the Transmission Control Protocol, a reliable Layer 4 protocol that uses a three-way handshake to create reliable connections across a network. Hosts may also access IPv6 networks via IPv4 this is called tunneling. Systems may be “dual stack” and use both IPv4 and IPv6 simultaneously. Too few available IPv4 addresses in a world where humans (and their devices) outnumber them is a fundamental problem: This was one of the factors leading to the creation of IPv6, which uses much larger, 128-bit, addresses. A 32-bit address field allows 2 32, or nearly 4.3 billion, addresses.
IPv4 uses 32-bit source and destination addresses, usually shown in “dotted quad” format (e.g., “192.168.2.4”). If connections or reliability are required, they must be provided by a higher-level protocol carried by IP, such as TCP. It is also connectionless and unreliable, providing “best effort” packet delivery. IPv4 is Internet Protocol version 4, commonly called “IP.” It is simple, designed to carry data across networks.
Newer EUI-64 MAC addresses are 64 bits long. Historically, MAC addresses were 48 bits long, divided in halves: The first 24 bits represented the Organizationally Unique Identifier ( OUI) the last 24 bits, a serial number (formally called an extension identifier).
0 kommentar(er)
