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

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

The following reply was made to PR kern/52554; it has been noted by GNATS.

From: Roy Bixler <rcbixler%nyx.net@localhost>
To: Ryota Ozaki <ozaki-r%netbsd.org@localhost>
Cc: Hisashi T Fujinaka <htodd%twofifty.com@localhost>,
        "gnats-bugs%NetBSD.org@localhost" <gnats-bugs%netbsd.org@localhost>,
        gnats-admin%netbsd.org@localhost, netbsd-bugs%netbsd.org@localhost
Subject: Re: kern/52554: IPv6 connections not routing to default gateway
Date: Mon, 2 Oct 2017 08:09:10 -0600

 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