[ntp:questions] 1 Machine, 2 NICs, 2 Instances of ntpd; Possible?

Maarten Wiltink maarten at kittensandcats.net
Tue Mar 11 20:54:57 UTC 2008

"Steve Kostecke" <kostecke at ntp.org> wrote in message
news:slrnftdkhp.knr.kostecke at stasis.kostecke.net...
> Currently NTP uses port 123/UDP for both the source and destination
> port. What you are proposing would require the use of a different source
> port to work on a single-homed host. This would result in a DOS when
> polling a server that enforces the NTP port.

I'm no IP wizard, but isn't there a SO_REUSEPORT flag or something
like that?

Anyway, I frankly doubt that requiring a specific source port is
still a good thing. Dit it ever accomplish anything above testing
that the sender has root on the remote machine? By now, it mostly
serves to chase off innocent NATted clients.

> Another thing to consider is the fact that you would now have two
> processes which both require high priority access to the system clock.

I can see how that would be a party killer. But the current, monolithic
NTP can't discipline the clock and answer polls at the exact same time,
either. The obvious choice would be to give the client part priority
over the server part. Things might actually get *better*.

>> [...] Decoupling always adds complexity at the interface. But as a
>> software guy I appreciate the focus it adds to the decoupled modules.
> I'd point out that the source is available for anyone to modify, but
> that statement seems to interpreted as an attempt to stifle discussion.

Well, I appreciate the source being available and all, but unfortunately
I already have a hobby to take up six nights a week. Plus, while patches
might be accepted, I doubt that a major rewrite of the entire codebase
would. Sorry. Sometimes I wish I were still twenty-two and had the
patience to do it, and the perseverence to get it changed. At thirty-
seven, all I have left is the questionable sideline-based wisdom to
see room for improvement.

Maarten Wiltink

More information about the questions mailing list