[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. . . .
HTH
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