Re: "accept_ra 1" vs "accept_ra 2" in interfaces configuration-file
On Mon, Aug 20, 2018 at 7:55 AM Andy Smith <email@example.com> wrote:
> Hi Martin,
> On Mon, Aug 20, 2018 at 05:12:56AM +0300, Martin T wrote:
> > According to "man interfaces" "accept_ra 1" makes interface to accept
> > IPv6 RA messages. "accept_ra 2" does the same and in addition, it also
> > enables forwarding. What does the forwarding mean in this context? One
> > could think, that it modifies the /proc/sys/net/ipv6/conf/*/forwarding
> > file(s), but this does not seem to be the case.
> If forwarding = 1 then by default RAs will not be accepted. Setting
> accept_ra to 2 allows RAs to be accepted even when forwarding = 1.
> Changing the values of either forwarding or accept_ra does not alter
> the values of the other. Only the behaviour of the system.
> Back in 2011 this was a hard-won battle:
Thanks for this very informative blog post! However, setting the
"net.ipv6.conf.all.forwarding" to 1 in /etc/sysctl.conf and
"accept_ra" to 2 in /etc/network/interfaces for ISP facing
interface(eth0) didn't work for me. I expected SLAAC to work, but it
didn't. I'm running kernel version 4.9.0. Settings can be seen below:
# sysctl net.ipv6.conf.all.forwarding
net.ipv6.conf.all.forwarding = 1
# sysctl net.ipv6.conf.eth0.accept_ra
net.ipv6.conf.eth0.accept_ra = 2
When I set the "net.ipv6.conf.all.forwarding" to 0 and reboot the
router, then SLAAC works. What might cause this?