IPPROTO_IPV6(2const) IPPROTO_IPV6(2const)

IPPROTO_IPV6 - Linux IPv6 protocol socket options

Standard C library (libc-lc)

#include <netinet/in.h>  /* Definition of IP* constants */
#include <sys/socket.h>
int setsockopt(int sockfd, IPPROTO_IPV6, int opt,
               const void val[size], size_t size);
int getsockopt(int sockfd, IPPROTO_IPV6, int opt,
               void val[size], size_t size);

IPv6 supports some protocol-specific socket options that can be set with setsockopt(2) and read with getsockopt(2). The socket option level for IPv6 is IPPROTO_IPV6. A boolean integer flag is zero when it is false, otherwise true.

The following socket options are supported.

See setsockopt(2). See ipv6(7).

opt is invalid.

POSIX.1-2001.

setsockopt(2), cmsg(3), ipv6(7)

2026-01-05 Linux man-pages 6.17