Re: install/57864: Install first tries to load from cdn.netbsd.org using ipv6

[Robert Elz <kre%munnari.OZ.AU@localhost>]

The following reply was made to PR install/57864; it has been noted by GNATS.

From: Robert Elz <kre%munnari.OZ.AU@localhost>
To: gnats-bugs%netbsd.org@localhost
Cc: 
Subject: Re: install/57864: Install first tries to load from cdn.netbsd.org using ipv6
Date: Thu, 18 Jan 2024 18:01:55 +0700

     Date:        Thu, 18 Jan 2024 05:55:02 +0000 (UTC)
     From:        Martin Husemann <martin%duskware.de@localhost>
     Message-ID:  <20240118055502.15D861A9239%mollari.NetBSD.org@localhost>
 
   |   - fix the DHCP setup to not provide a default route for IPv6
 
 Actually one minor correction on that - it is fine for the
 end hosts to have a default route to the local router, is
 is that router (and any others on the network) which must
 not have a default route (where is it sending stuff?   And
 it needs to be sending back ICMPv6 'unreachable' and the
 NetBSD stack needs to notice that in SYN SENT state, and fail)
 
 If the latter part doesn't work, then the host default routes
 need to go as well, which unless the LAN is very simple, will
 likely mean every host would need local static route config,
 or to be config'd to be a router and run a routing daemon.
 Hosts don't normally learn routing details, beyond what they
 can interpret from redirects.
 
 Either way the v6 connect attempt will still happen, but be
 rejected quickly.
 
 It might also be possible to config your local DNS stub resolver
 to return v4 addresses before v6 in the addrlist returned to
 the app.
 
 kre