recent RTADV changes

[Michael van Elst]

Recently the handling of IPv6 router advertisements was changed
so that you can enable/disable this for each interface individually.

According to ndp(8):
accept_rtadv
Specify whether or not to accept Router Advertisement
messages received on the interface. Note that the kernel
does not accept Router Advertisement messages unless the
net.inet6.ip6.accept_rtadv variable is non-0, even if the
flag is on. This flag is set to 1 by default.

Unfortunately it is not set to 1 by default, but the global
setting from net.inet6.ip6.accept_rtadv is copied when an
interface is attached. The sysctl variable however is configured
only in rc.d/network for ip6mode=autohost.

As a result a network using router advertisements is broken by default
as the interfaces are attached before rc.d/network is running.

There are two solutions to restore the previous behaviour for autohosts.

- teach rc.d/network to also set the private setting of each
attached interface for an autohost. It is unclear what should
happen with the flags for non-autohosts.

- unconditionally enable the accept_rtadv flag for each interface
(as documented). People needing fine grain control now have to
_disable_ the flag for interfaces that shouldn't do autoconfiguration.


Suggestions?


Greetings,
--
Michael van Elst
Internet: ***@serpens.de
"A potential Snark may lurk in every tree."

[David Young]

Post by Michael van Elst
Recently the handling of IPv6 router advertisements was changed
so that you can enable/disable this for each interface individually.
accept_rtadv
Specify whether or not to accept Router Advertisement
messages received on the interface. Note that the kernel
does not accept Router Advertisement messages unless the
net.inet6.ip6.accept_rtadv variable is non-0, even if the
flag is on. This flag is set to 1 by default.
Unfortunately it is not set to 1 by default, but the global
setting from net.inet6.ip6.accept_rtadv is copied when an
interface is attached. The sysctl variable however is configured
only in rc.d/network for ip6mode=autohost.

I think that the per-interface accept_rtadv setting should be a
tri-state---on, off, or use global setting---that defaults to using the
global setting.

Dave