[ntp:questions] nptq -p slowness

Richard B. Gilbert rgilbert88 at comcast.net
Fri Jan 26 20:22:24 UTC 2007

Serge Bets wrote:

> 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
> servers)?

Most TCP/IP stacks have a file (/etc/resolv.conf) that contains:
"domain <mydefault domain>"
"nameserver <isp_server1>"
"nameserver <isp_server2>"

The "domain" entry tells your resolver which domain to use if none is 
specified.  If you don't have a domain statement. . . .


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