See also Communication Debugging - Status, tracing, and debugging communications and protocols.

nc(1) - Arbitrary tcp and udp connections and listens. {oss}

ipf(1) - alters packet filtering lists for IP packet input and output {oss}

ipftest(1) - test packet filter rules with arbitrary input. {oss}

ipnat(1) - user interface to the NAT {oss}

ipsecadm(1) - interface to setup IPSec {oss}

Applications and Utilities

socket (2) - create an endpoint for communication {oss}

listen (2) - listen for connections on a socket {oss}

accept (2) - accept a connection on a socket {oss}

bindresvport (3) - bind a socket to a privileged IP port {oss}

bind (2) - bind a name to a socket {oss}

connect (2) - initiate a connection on a socket {oss}

write writev (2) - write output {oss}

send sendto sendmsg (2) - send a message from a socket {oss}

read readv (2) - read input {oss}

recv recvfrom recvmsg (2) - receive a message from a socket {oss}

getpeername (2) - get name of connected peer {oss}

getsockname (2) - get socket name {oss}

getsockopt setsockopt (2) - get and set options on sockets {oss}

ioctl (2) - control device {oss}

shutdown (2) - shut down part of a full-duplex connection {oss}

select (2) - synchronous I/O multiplexing {oss}

poll (2) - synchronous I/O multiplexing {oss}

Libraries and Functions

(The following links to subjects at this site retain your personalized selections.)

Higher level implementation is covered at Client Server Implementation - clients and servers (listeners) in general. Technologies, frameworks

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