With mpd5 dynamic interfaces, will rtadvd automatically listen?

From: Neel Chauhan <nc_at_FreeBSD.org>
Date: Mon, 07 Mar 2022 19:09:14 UTC
Hi freebsd-net@,

I'm thinking about setting up a dual-stack L2TP server for VPN purposes, 
and found that mpd5 lacks good dual-stack support outside of IPv6CP, so 
we have to do a makeshift approach.

Will rtadvd automatically listen on the mpd5 ng* interface if the said 
interface has a public IPv6 address and a user connects (w/ default 
config)? Or will I need to trigger rtadvd manually?

Yes, I could use one rtadvd per connection, but that isn't really 

-Neel (nc@)