[ntp:questions] "Trapping" in ntpd

Rob pse at nospam.com
Wed Oct 3 13:33:59 UTC 2007

Steve wrote:

> Look for ./scripts/monitoring/ntptrap on the distribution source tree.

Thanks Steve.  It looks like trapping is really only useful for debugging.
Even then, trapping may be of limited value.  The readme in this directory

"This script convinced me that ntp trap messages are only of little use"

The readme also has an important warning ---

"Please think twice before starting remote XNTP daemons!!!!
Monitoring may increase the load of the daemon monitored and may 
increase the network load significantly"

As a result, in my view, it is important to have "notrap" and/or "noquery"
on each restrict line in your ntp.conf.  

Since ntptrap is a perl script to log ntp trap messages, I suspect
specifying noquery in a restrict line will by implication block all traps.
 (i.e. when specify noquery in a restrict line in ntp.conf, there is no
 value in adding "notrap" on the same restrict line).  Of course, there is
 no harm is also adding notap to restrict lines that have noquery on them.

If my understanding is incorrect, I hope someone will correct me. :-)


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