IP_BIND_ADDRESS_NO_PORT(2const) — Linux manual page

IP_BIND_ADDRESS_NO_PORT(2const)           IP_BIND_ADDRESS_NO_PORT(2const)

NAME         top

       IP_BIND_ADDRESS_NO_PORT - don't reserve an ephemeral port

LIBRARY         top

       Standard C library (libc, -lc)

SYNOPSIS         top

       #include <netinet/in.h>  /* Definition of IP* constants */
       #include <sys/socket.h>

       int setsockopt(int sockfd, IPPROTO_IP, IP_BIND_ADDRESS_NO_PORT,
                      const int *enable, sizeof(int));

DESCRIPTION         top

       Inform the kernel to not reserve an ephemeral port when using
       bind(2) with a port number of 0.  The port will later be
       automatically chosen at connect(2) time, in a way that allows
       sharing a source port as long as the 4-tuple is unique.

ERRORS         top

       See IPPROTO_IP(2const).  See setsockopt(2).  See ip(7).

HISTORY         top

       Linux 4.2.

SEE ALSO         top

       IPPROTO_IP(2const), setsockopt(2), ip(7)

COLOPHON         top

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Linux man-pages 6.18            2025-11-25IP_BIND_ADDRESS_NO_PORT(2const)

Pages that refer to this page: IPPROTO_IP(2const)

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