How to generate IPv6 RA without any prefixes?

[sthaug at nethelp.no]

> >>> In IPv6 it should be possible to generate a Router Advertisement which
> >>> contains no prefix options (the idea being that I want the host to
> >>> populate its default router list but nothing else). However, I cannot
> >>> seem to get rtadvd to do this.
> 
> Can you open a PR and get it assigned to net@ or bz@, so this won't be
> lost?  I am not sure I'll be able to look the next 10 days.

I have just submitted a PR with the one-line description "rtadvd needs
to allow RA without a prefix info option", but haven't yet received a
confirmation back.

Steinar Haug, Nethelp consulting, sthaug at nethelp.no