If you are peering with a machine that goes down, or that
stops running an NTP daemon, you will see screams in your
syslog of the form:
	xntpd[26005]: recvfrom() fd=7: Connection refused
Worse, these are logged with priority LOG_ERR, which is
supposed to mark fairly important problems.

 These exist because Linux + glibc return errors on
recvfrom() that are due to a previous UDP sendto() on
the same socket failing because of various detectable
problems. The xntp3 code is not expecting this to
happen, and thinks that these are real recvfrom()
errors.

 These syslog messages are annoying. I've developed a
patch to muzzle them for connection refused, host down,
and host/net unreachables, if people are interested.