Re: IPv6 routing(?)

[Jan Danielsson <jan.m.danielsson%gmail.com@localhost>]

On 2016-11-18 03:35, Andy Ruhl wrote:
[---]
> Packets going out but not coming back seems to be the key.

   Exactly, and ..

> IPv6 likes to have ICMP enabled for path mtu discovery, might look into that.

   .. I think you're on to it here.

   So what happens is that the echo request is sent out from my host
(say it has address X), then I see then Cisco modem (ISP's equipment)
make a Neighbor Solicitation for the address X, but my NetBSD router
(which knows about address X according to "ndp -a") never replies.

   The issue seems to be that the router isn't acting as an "NDP proxy"
(analogous to an ARP proxy in IPv4, I assume).

   What do I need to do to make it respond to such requests?  Linux
appears to have a sysctl knob called net.ipv6.conf.all.proxy_ndp, is
there such a thing for NetBSD?  I looked through the sysctl list, but
couldn't find any obvious candidates.

   (NetBSD/amd64 -7).

> Also wondering if there is some issue receiving traffic, like you're
> firewalled? If you don't see ping replies they could be getting
> dropped before you can see them. Woud be nice to confirm by sniffing
> the outside interface somehow.

    I'm using npf on my NetBSD router, but it's configured to allow
everything currently, so it shouldn't be an issue.

   /Jan