[ntp:questions] no server suitable for synchronization?

Zhang Weiwu zhangweiwu at realss.com
Mon Feb 21 13:58:52 UTC 2005


Brad Knowles wrote:
> At 8:56 PM +0800 2005-02-21, Zhang Weiwu wrote:
> 
>>  sappho ~ # ntpdate -v 2.pool.ntp.org
>>  21 Feb 20:50:06 ntpdate[3078]: ntpdate 4.2.0a at 1.1190-r Tue Dec  7 
>> 21:59:12
>>  CST 2004 (1)
>>  21 Feb 20:50:10 ntpdate[3078]: no server suitable for synchronization 
>> found
>>  (querying 0.pool.ntp.org and 1.pool.ntp.org fails alike)
>>
>>  Since I noticed nobody else is talking about it on the web, I guess
>>  it's either my ICP or the new great Chinese firewall. Any suggestions?
> 
> 
>     It would help to have more debugging information, specifically to 
> know which particular servers (by IP address) you were trying to query.  
> Sometimes pool.ntp.org has a hiccup, and the servers that are returned 
> are not actually functioning correctly.  This is rare, but it does 
> sometimes happen.

I will try to figure out how to detect which IP address am I querying. 
However I don't think it's the fault of a particular server because I 
have tried [123].pool.ntp.org for a long time and I have cronjob tries 
to correct time each 1 hour, but my time is still incorrect after 
several weeks.

>     If you could tell us what IP addresses you were querying, and give 
> us more information as to the process ntpdate went through at the time, 
> we could give you an idea of whether those servers should be functional 
> and whether you might be experiencing a firewall problem.

I am not experienced enough to sniff network traffic, the only thing I 
could do I guess is to take this debug info.

There is a NAT firewall in our company but I think it's no problem 
because this firewall is configured by me to only stop outside connect 
to local port but not vise-versa.

sappho ~ # ntpdate -d 1.pool.ntp.org
21 Feb 21:57:01 ntpdate[3180]: ntpdate 4.2.0a at 1.1190-r Tue Dec  7 
21:59:12 CST 2004 (1)
Looking for host 1.pool.ntp.org and service ntp
host found : rosehip.exnet.com
transmit(195.137.27.138)
transmit(195.137.27.138)
transmit(195.137.27.138)
transmit(195.137.27.138)
transmit(195.137.27.138)
195.137.27.138: Server dropped: no data
server 195.137.27.138, port 123
stratum 0, precision 0, leap 00, trust 000
refid [195.137.27.138], delay 0.00000, dispersion 64.00000
transmitted 4, in filter 4
reference time:    00000000.00000000  Thu, Feb  7 2036 14:28:16.000
originate timestamp: 00000000.00000000  Thu, Feb  7 2036 14:28:16.000
transmit timestamp:  c5c46731.c5ef5232  Mon, Feb 21 2005 21:57:05.773
filter delay:  0.00000  0.00000  0.00000  0.00000
          0.00000  0.00000  0.00000  0.00000
filter offset: 0.000000 0.000000 0.000000 0.000000
          0.000000 0.000000 0.000000 0.000000
delay 0.00000, dispersion 64.00000
offset 0.000000

21 Feb 21:57:06 ntpdate[3180]: no server suitable for synchronization found



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