---
name: "gnutls_dtls_set_mtu"
section: "3"
platform: "linux"
package: "gnutls"
version: "3.8.13-3"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/gnutls_dtls_set_mtu"
---

# gnutls\_dtls\_set\_mtu(3)

API function

## NAME

gnutls\_dtls\_set\_mtu - API function

## SYNOPSIS

**#include \<gnutls/dtls.h\>**

**void gnutls\_dtls\_set\_mtu(gnutls\_session\_t** *session***, unsigned int** *mtu***);**

## ARGUMENTS

- gnutls\_session\_t session

  is a **gnutls\_session\_t** type.

- unsigned int mtu

  The maximum transfer unit of the transport

## DESCRIPTION

This function will set the maximum transfer unit of the transport that DTLS packets are sent over. Note that this should exclude the IP (or IPv6) and UDP headers. So for DTLS over IPv6 on an Ethernet device with MTU 1500, the DTLS MTU set with this function would be 1500 - 40 (IPV6 header) - 8 (UDP header) = 1452.

## SINCE

3\.0

## REPORTING BUGS

Report bugs to \<bugs@gnutls.org\>.\
 Home page: https://www.gnutls.org

## COPYRIGHT

Copyright © 2001-2023 Free Software Foundation, Inc., and others.\
 Copying and distribution of this file, with or without modification, are permitted in any medium without royalty provided the copyright notice and this notice are preserved.

## SEE ALSO

The full documentation for **gnutls** is maintained as a Texinfo manual. If the /usr/share/doc/gnutls/ directory does not contain the HTML form visit

- https://www.gnutls.org/manual/