What packet modes do we support?

[Hal Murray]

Where is that documented?  

Context is I'm working on documentation.  Often, I'm removing stuff that is 
no longer relevant.  Sometimes that requires checking the code.  Some of the 
code needs cleaning up too.  I think - maybe I just don't understand it yet.

We treat peer in ntp.conf as an alias for server.
So we don't send MODE_ACTIVE.
It looks like we respond to MODE_ACTIVE with MODE_PASSIVE.

It looks like we can send MODE_BROADCAST.
I assume that's for compatibility.
Has anybody tried it?
(That will require an old server, but we probably want one for testing 
anyway.)

I assume we ignore received  MODE_BROADCAST packets, but I haven't confirmed 
that by reading the code.

The question that got me here is the nopeer restrict option.  Do we need it 
any more?  I think we no longer setup any unsolicited peers.  The pool code 
used to do that, but not any more.  I think the peer command on another 
server used to do that, but I'm pretty sure we don't do that any more.

Related, there is a table or two that used to be needed to handle received 
packets.  I think we can simplify things by bypassing them, but that depends 
on understanding what packets we allow.



-- 
These are my opinions.  I hate spam.