Re: kern/52554: IPv6 connections not routing to default gateway

[Roy Bixler <rcbixler%nyx.net@localhost>]

On Mon, Oct 02, 2017 at 04:26:46PM +0900, Ryota Ozaki wrote:
> On Mon, Oct 2, 2017 at 9:34 AM, Roy Bixler <rcbixler%nyx.net@localhost> wrote:
> > The only question I still have is whether the
> > DHCP negotiation is an issue.  Somehow, NetBSD 7.1 consistently picks
> > the working IPv6 router and NetBSD-8 and -current almost always pick
> > another router, which doesn't work.  I'm still trying to find
> > more information about our local network configuration.
> 
> dhcpcd -U -6 wm0 may provide useful information. Or if dhcpcd doesn't
> handle RA, ndp -r; ndp -p may provide something useful instead.

I asked the network admin. and he tells me that that IPv6 routers are
advertising priorities and the router that works has the highest
priority.  He says that it's an option that was put into the Linux
kernel a few years ago.  The option, CONFIG_IPV6_ROUTER_PREF, quotes
RFC4191 as a reference.  From looking at the dhcp client logs, I can
see that it's getting advertisements from all of the routers and it
just picks the first one (i.e. sets its default route according to it)
and disregards the others.  I still wonder why this doesn't happen
with NetBSD 7.1.

-- 
Roy Bixler <rcbixler%nyx.net@localhost>
"The fundamental principle of science, the definition almost, is this: the
sole test of the validity of any idea is experiment."
-- Richard P. Feynman