Re: Using NTP

[Havard Eidnes <he%NetBSD.org@localhost>]

> From /var/run/rc.log:
>
> [running /etc/rc.d/ntpdate]
> Setting date via ntp.
> Exiting, name server cannot be used: Temporary failure in name
> resolution (2)/etc/rc.d/ntpdate exited with code 1
> 
> From /etc/rc.conf:
> 
> ntpd=YES             ## 'ntp' == Network TIME Protocal
> ntpdate=YES      ntpdate_hosts="2.netbsd.pool.ntp.org"
>
> What is wrong with these lines in rc.conf ??

They create a circular dependency.

DNS name resolution these days in many cases rely on DNSSEC.
xDNSSEC depends on a semi-accurate local clock on your DNS
recursive server, and if that is "yourself", something you don't
have if your battery cell for your real-time clock chip is toast.
If you don't have semi-accurate time already, you will get DNS
name lookup errors (SERVFAIL, typically), and ntpdate ends up not
being able to set the clock to fix the underlying issue for the
DNS lookups.

In many cases I use IP addresses in ntp.conf but obviously you
can just supply a list of IP addresses in ntpdata_hosts as well
if you prefer to break the circular dependency.

Regards,

- Håvard