"default send string"

[Dan Drown]

Quoting Hal Murray via devel <devel at ntpsec.org>:
> I'm looking at the cruft a pool server receives.
>
> I see UDP packets where the body is ASCII text of "default send string".
>
> I'm pretty sure I've seen UDP code with that string.  I can't find it in our
> code.  Does anybody know where it comes from?

Might be from an F5 that is trying to monitor the NTP pool  
(incorrectly) - https://support.f5.com/csp/article/K85412902