[ntp:questions] nptq -p slowness

Serge Bets serge.bets at NOSPAM.laposte.invalid
Fri Jan 26 15:04:38 UTC 2007

Hello everybody,

With ntp 4.2.4, I strangely get a very slow display of the ntp -p
billboard. Example:

| $ ntpq -p
|      remote           refid      st t when poll reach   delay   offset  jitter
| ==============================================================================
|  SHM(0)          .DCF.            0 l    -   64    0    0.000    0.000   0.004
| *LOCAL(0)        .LOCL.           8 l   60   64  377    0.000    0.000   0.004

This takes more than a minute to display, line by line. A named querylog
shows that it's due to DNS resolver delays until timeout. It seems that
when showing a refid, ntpq does a DNS A request on the name
"DCF.<localdomain>", gets immediatly a "does not exist" authoritative
answer. Then it does an A request on "DCF" alone, without answer until
timeout. Then only ntpq displays the line and ".DCF." with the added
dots around. The same happens for other refids LOCL, INIT, and such.
However when the refid is an ntp server, it's displayed as dotted quad
immediatly, without delay.

Now I have 2 questions:

 - Why does ntpq request A on refids? I remember the good old reverse
PTR resolution long ago when refids were IPv4s. But why an A?

 - What's broken on my system so that not qualified hostnames are not
considered local (my named forwards those A requests to my provider's

Thankfully, Serge.
Serge point Bets arobase laposte point net

More information about the questions mailing list