IP_RECVTTL(2const)                                          IP_RECVTTL(2const)

NAME
       IP_RECVTTL - enable IP_TTL control message

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, int opt,
                      const int *enable, sizeof(int));

DESCRIPTION
       When this flag is set, pass a IP_TTL(2const) control message with the
       time-to-live field of the received packet as a 32 bit integer.

       Not supported for SOCK_STREAM sockets.

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

VERSIONS
       Some BSD sockets implementations also provide an IP_RECVTTL option, but
       an ancillary message with type IP_RECVTTL is passed with the incoming
       packet.  This is different from the IP_TTL(2const) option used in
       Linux.

HISTORY
       Linux 2.2.

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

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