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Character Generator Protocol
open-in-new
<p>The Character Generator Protocol (CHARGEN) is a service of the <a href="/facts/Internet_Protocol_Suite/KNkxtSpw">Internet Protocol Suite</a> defined in <a href="/facts/RFC_(identifier)/esftTvE7">RFC</a> <a href="https://datatracker.ietf.org/doc/html/rfc864">864</a> in 1983 by <a href="/facts/Jon_Postel/7FIv4teq">Jon Postel</a>. It is intended for testing, debugging, and measurement purposes. The protocol is rarely used, as its design flaws allow for ready misuse. </p><p>A host may connect to a server that supports the Character Generator Protocol on either <a href="/facts/Transmission_Control_Protocol/WW4sPrt9">Transmission Control Protocol</a> (TCP) or <a href="/facts/User_Datagram_Protocol/dxLU0D6q">User Datagram Protocol</a> (UDP) <a href="/facts/Port_number/ygoHVKNC">port number</a> 19. Upon opening a TCP connection, the server starts sending arbitrary characters to the connecting host and continues until the host closes the connection. In the UDP implementation of the protocol, the server sends a UDP datagram containing a random number (between 0 and 512) of characters every time it receives a datagram from the connecting host. Any data received by the server is discarded. </p>