Re: Crash related to VLANs in Oct 18th -current

[Roy Marples <roy%marples.name@localhost>]

On 23/10/2017 14:08, Thor Lancelot Simon wrote:
> I think it is safe to say that an interface which is participating
> in an interface stack such as vlan or agr should never be given an
> address unless the user has explicitly configured the system to do
> so.  The sane default is to give addresses to the leaf interfaces
> only (e.g. vlan) not the root nor intermediate nodes (wm, agr, etc --
> noting of course that any of these interfaces _could_ be the leaf,
> but in fact are not).

The mere act of bringing an interface up will generally assign it an
IPv6 link-local address.
dhcpcd doesn't change this behaviour.

Luckily this can be disabled in dhcpcd quite easy:
# Global default is IPv6 on all interfaces
interface wm0
    noipv6 # Disable IPv6 on wm0

Or reverse the logic
noipv6 # Disable IPv6 globally
interface wm0
    ipv6 # Enable IPv6 for wm0

Or just disallow the interface entirely:
denyinterfaces wm0

Or just allow some interfaces whilst denying others:
allowinterfaces wm0

And you can stop the kernel from doing this too if not using dhcpcd
ndp -i wm0 -- -auto_linklocal

Roy