IP_TRANSPARENT(2const)                                  IP_TRANSPARENT(2const)

NAME
       IP_TRANSPARENT - transparent proxying

LIBRARY
       Standard C library (libc, -lc)

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

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

DESCRIPTION
       Setting this boolean option enables transparent proxying on this
       socket.

       This socket option allows the calling application to bind to a nonlocal
       IP address and operate both as a client and a server with the foreign
       address as the local endpoint.

       This requires that routing be set up in a way that packets going to the
       foreign address are routed through the TProxy box (i.e., the system
       hosting the application that employs the IP_TRANSPARENT socket option).

       Enabling this socket option requires superuser privileges (the
       CAP_NET_ADMIN or CAP_NET_RAW capability).

       TProxy redirection with the iptables TPROXY target also requires that
       this option be set on the redirected socket.

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

STANDARDS
       Linux.

HISTORY
       Linux 2.6.24.

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

Linux man-pages 6.17              2025-11-25            IP_TRANSPARENT(2const)