[ntp:questions] Re: time.ucla.edu is closed

Wolfgang S. Rupprecht wolfgang+gnus20060903T232205 at dailyplanet.dontspam.wsrcc.com
Mon Sep 4 06:36:07 UTC 2006

Felix Tilley <fetilley at cyberbromo.int> writes:
> I don't know if NTP uses TCP, UDP or both.  All I know is time.ucla.edu
> does not respond to ntpdate (Linux version).  This started a few days ago.

I think you might want to use something other than nmap to test that
they closed the server.  Nmap for 123/tcp will fail because ntp
doesn't use tcp.  Nmap for 123/udp probably won't give any meaningful
output either.  The nmap test for udp just tells you if talking to the
port causes an ICMP port-unreachable to be sent.  If it is filtered by
a firewall that drops 123/udp then nmap will claim the port is "open".
If ntp is running but ignoring non-approved hosts, then nmap similarly
will claim it is "open".

Personally, I used "ntpdate -d" to see if a host is answering.  ;-) 
<I guess I should duck and run now...>

Wolfgang S. Rupprecht                http://www.wsrcc.com/wolfgang/

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