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IP_MTU(2const) IP_MTU(2const)

NAME

IP_MTU - path maximum transmission unit size

LIBRARY

Standard C library (libc-lc)

SYNOPSIS

#include <netinet/in.h>  /* Definition of IP* constants */
#include <sys/socket.h>
int getsockopt(int sockfd, IPPROTO_IP, IP_MTU,
               int *val, sizeof(int));

DESCRIPTION

Retrieve the current known path MTU of the current socket.

IP_MTU is valid only for getsockopt(2), and can be employed only when the socket has been connected.

ERRORS

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

STANDARDS

Linux.

HISTORY

Linux 2.2.

SEE ALSO

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

2025-11-25 Linux man-pages (unreleased)