DISCARD
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The DISCARD protocol is an internet protocol defined in RFC 863. It is intended for testing and measurement purposes.
A host may send data to a host that supports the DISCARD protocol, on either TCP or UDP port 9. Everything sent to the server is discarded. No response is sent back.
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[edit] Inetd implementation of DISCARD
On Linux, FreeBSD, and other UNIX-like operating systems a discard server is built into the inetd daemon. The discard service is usually not enabled by default. It may be enabled by adding the following lines to the file /etc/inetd.conf and telling inetd to reload its configuration:
discard stream tcp nowait root internal discard dgram udp wait root internal
[edit] Examples of use
- The TCP/UDP equivalent of /dev/null. Such a service is guaranteed to receive what is sent to it and can be used for debugging TCP and/or UDP code requiring a guaranteed reception of payload sent.
