forwarding

file: /proc/sys/net/ipv6/conf/interface/forwarding
variable: net.ipv6.conf.interface.forwarding
Official reference

Enable global IPv6 forwarding between all interfaces.

IPv4 and IPv6 work differently here; e.g. netfilter must be used to control which interfaces may forward packets and which not.

This also sets all interfaces’ Host/Router setting ‘forwarding’ to the specified value. See below for details.

This referred to as global forwarding.

Nb: per interface setting (where “interface” is the name of your network interface); “all” is a special interface: changes the settings for all interfaces.


layout: sysctl title: forwarding sysctl-category: net.ipv6 sysctl-file: /proc/sys/net/ipv6/conf/interface/forwarding sysctl-variable: net.ipv6.conf.interface.forwarding source: https://www.kernel.org/doc/Documentation/networking/ip-sysctl.txt — Configure interface-specific Host/Router behaviour.

Note: It is recommended to have the same setting on all interfaces; mixed router/host scenarios are rather uncommon.

Possible values are: 0 Forwarding disabled 1 Forwarding enabled

FALSE (0):

By default, Host behaviour is assumed. This means:

  1. IsRouter flag is not set in Neighbour Advertisements.
  2. If accept_ra is TRUE (default), transmit Router Solicitations.
  3. If accept_ra is TRUE (default), accept Router Advertisements (and do autoconfiguration).
  4. If accept_redirects is TRUE (default), accept Redirects.

TRUE (1):

If local forwarding is enabled, Router behaviour is assumed. This means exactly the reverse from the above:

  1. IsRouter flag is set in Neighbour Advertisements.
  2. Router Solicitations are not sent unless accept_ra is 2.
  3. Router Advertisements are ignored unless accept_ra is 2.
  4. Redirects are ignored.

Default: 0 (disabled) if global forwarding is disabled (default), otherwise 1 (enabled).

Nb: per interface setting (where “interface” is the name of your network interface); “all” is a special interface: changes the settings for all interfaces.

source