ntp problem

[Lisa Casey]

Hi,

Running FreeBSD 5.3  IN /etc/ntp.conf I have:

server time.nist.gov prefer
server tock.gpsclock.com
driftfile /etc/ntp.drift
logfile /var/log/ntp.log

If I run ntpdate from a prompt, I get the following  error message:

# ntpdate
20 Apr 12:02:08 ntpdate[50109]: no servers can be used, exiting

But if I type:

ntpdate time.nist.gov   it will update the time. Is there something wrong with my /etc/ntp.conf file?

Lisa Casey