Re: [dns-privacy] Discovery of DNS over (not 53) and ALPN

["Martin Thomson" <[e-mail]>]

On Mon, Dec 16, 2019, at 13:40, Tom Pusateri wrote:
> 
> 
> > On Dec 15, 2019, at 7:35 PM, Martin Thomson <[e-mail]> wrote:
> > 
> >> So, let's back up a step: are people interested in using DHCP and RA as 
> >> part of the discovery story here or not?
> > 
> > I am.
> > 
> > I tend to think that https://thpts.github.io/draft-peterson-dot-dhcp/draft-peterson-dot-dhcp.html is a reasonable start here. Sure, it makes some assumptions, and leaves some of the harder 8310-style questions unanswered, but that's where I think we should be paying more attention anyway.
> 
> This is at least the fourth list that DoT discovery over DHCP has been 
> discussed (see DoH, DNSOP, and DRIU).
> 
> In the previous three times, it was rejected as not a trustworthy source.
[...]
> https://www.youtube.com/watch?v=cfEX8zuoRAA

I refreshed my memory here and I my interpretation of Ted's presentation is perhaps different than what you took away.  I could make one of two inferences:

1. Don't allow the network to configure DNS.  You can't trust it.

2. Be clearer about the trust model when you allow the network to provide this information.

There was a bunch of other noise about the shortcomings of DHCP, but this was the central point.

The first might be read as a firm argument for certain DoH deployment arrangements.  Arrangements that have proven to be highly controversial.  Your own introduction to the next presentation acknowledges the shortcoming and even identified a trust model or two that might fit within the remit of the second option.