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man pages section 8: System Administration Commands

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Updated: Wednesday, July 27, 2022
 
 

in.discardd(8)

Name

in.discardd - UDP or TCP discard protocol service

Synopsis

/usr/lib/inet/in.discardd

FMRI

svc:/internet/discard:default

Description

The in.discardd service provides the server-side of the discard protocol. This protocol is used for debugging and bandwidth measurement and is available on both TCP and UDP transports through port 9.

The in.discardd service is an inetd(8) delegated smf(7) service. The in.discardd detects which transport is requested by examining the socket it is passed by the inetd daemon.

The discard service simply throws away any data it receives from the client.

TCP-based service

Once a connection is established, the in.discardd discards any data received. No response is generated. The connection remains open until the client terminates it.

UDP-based service

The in.discardd listens for UDP datagrams. When a datagram is received, the server discards it. No response is sent.

Attributes

See attributes(7) for descriptions of the following attributes:

ATTRIBUTE TYPE
ATTRIBUTE VALUE
Availability
service/network/legacy-network-services
Interface Stability
Committed

See Also

attributes(7), smf(7), inetadm(8), inetd(8)

Postel, J. RFC 863, Discard Protocol. Network Working Group. May 1983. https://tools.ietf.org/html/rfc863

Notes

The in.discardd service is managed by the service management facility, smf(7), under the service identifier:

svc:/internet/discard:default

Administrative actions on this service, such as enabling, disabling, or requesting restart, can be performed using svcadm(8). Responsibility for initiating and restarting this service is delegated to inetd(8). Use inetadm(8) to make configuration changes and to view configuration information for this service. The service's status can be queried using the svcs(1) command.

History

The in.discardd program and the svc:/internet/discard:default service were added in the Solaris 10 3/05 release. Prior to that, support for the discard service was provided as a builtin part of inetd(8) since the initial release of Solaris.

Support for IPv6 was added in Solaris 8.

The discard service was enabled by default in releases up through Solaris 9, but has been disabled by default since the Solaris 10 3/05 release.