Re: interface not getting address when net.ipv6.conf.all.forwarding is 1

[Pascal Hambourg <pascal.mail@plouf.fr.eu.org>]

Hello,

Folkert van Heusden a écrit :
> 
> - all systems but one get an ipv6 address sent by radvd on the server
> - the problem system ('thegate') ONLY gets an address if
>   net.ipv6.conf.all.forwarding is set to 0, as soon as it is set to 1
>   (and the vpn is restarted of course), then the interface does not get
>   an address

This is expected behaviour. A router does not get its configuration from
router advertisements, so stateless autoconfiguration is disabled when
forwarding is enabled.

See Documentation/networking/ip-sysctl.txt in the kernel source|doc. :

forwarding - BOOLEAN
	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.

	FALSE:

	By default, Host behaviour is assumed.  This means:

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

	TRUE:

	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.
	3. Router Advertisements are ignored.
	4. Redirects are ignored.

	Default: FALSE if global forwarding is disabled (default),
		 otherwise TRUE.