Subject: Re: [Ntp] Danny's Review (was Re: draft-ietf-ntp-roughtime-05: tag change makes implementation more complex)

From: Hal Murray <[email-masked]>
Date: Tue, 28 Sep 2021 17:33:27 -0700

Danny Mayer said:
> There is nothing to prevent me creating a protocol called SMOOTHTIME and
> throwing the ROUGHTIM value in the header to fool you. How has that made  the
> protocol unambiguous? That doesn't prevent tunneling, and yes I'm  familiar
> with this idea and I've seen the implementations. The only  proper way to
> handle this is deep packet inspection and fingerprinting.  Nothing else
> really works.

The bad guys can construct anything.  But what about bugs or stupidity?

I've been looking at the garbage arriving at a pool server.  Some of it is 
obviously garbage. But there is a lot of stuff that is not obviously good or 
bad.

As a general policy, is it worth a bit of space in a UDP packet to simplify 
sanity checking?

Another possibility would be to add a tag for the source package.  Yes, it can 
be forged, but it would help track down abuse from buggy code.

-- 
These are my opinions.  I hate spam.