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Old 12-05-2011, 01:47 AM   #1
Satyaveer Arya
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NTP Server Client Synchronization problem.


Hello Friends,

While doing synchronizaton activity on clients, by mistake I ran the command on server also.

I was using ntpdate -u <IP Address> on every clients for synchronization. Now when I run the above same command on clients it shows an error no server found for synchronization because I ran the ntpdate command on server also which shows the failed message for synchronizing time..

Can anyone please help me to solve this issue. I will be very thankful to you.
 
Old 12-05-2011, 01:52 AM   #2
corp769
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I would double check your configuration, and make sure that you can access your server. Can you at least ping it?
 
Old 12-05-2011, 02:03 AM   #3
Satyaveer Arya
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My NTP server is on RHEL5.3 and clients are also RHEL5.3

And yes I can access my server and ping it also

and one more thing is there that when I cross check dates on server and my clients, the dates on server and clients are running fine means they are synchronized that's why on server and clients it shows same time.

Then why do I get that error no server found for synchronization on clients after running the ntpdate -u <IP Address_of_server> command on clients.

Last edited by Satyaveer Arya; 12-05-2011 at 02:04 AM.
 
Old 12-05-2011, 02:07 AM   #4
corp769
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Could you post the configuration of your server?
 
Old 12-05-2011, 02:14 AM   #5
Satyaveer Arya
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# Permit time synchronization with our time source, but do not
# permit the source to query or modify the service on this system.
#restrict default kod nomodify notrap nopeer noquery
#restrict -6 default kod nomodify notrap nopeer noquery

# Permit all access over the loopback interface. This could
# be tightened as well, but to do so would effect some of
# the administrative functions.
restrict 127.0.0.1
#restrict -6 ::1

# Hosts on local network are less restricted.
restrict 172.16.0.0 mask 255.255.0.0 nomodify notrap

# Use public servers from the pool.ntp.org project.
# Please consider joining the pool (http://www.pool.ntp.org/join.html).
#server 172.16.104.35
#server 1.asia.pool.ntp.org

server 0.asia.pool.ntp.org
server 0.in.pool.ntp.org
#server 2.rhel.pool.ntp.org

#broadcast 192.168.1.255 key 42 # broadcast server
#broadcastclient # broadcast client
#broadcast 224.0.1.1 key 42 # multicast server
#multicastclient 224.0.1.1 # multicast client
#manycastserver 239.255.254.254 # manycast server
#manycastclient 239.255.254.254 key 42 # manycast client

# Undisciplined Local Clock. This is a fake driver intended for backup
# and when no outside source of synchronized time is available.
#server 172.16.104.35 # local clock
#fudge 127.127.1.0 stratum 10

# Drift file. Put this in a directory which the daemon can write to.
# No symbolic links allowed, either, since the daemon updates the file
# by creating a temporary in the same directory and then rename()'ing
# it to the file.
driftfile /var/lib/ntp/drift

# Key file containing the keys and key identifiers used when operating
# with symmetric key cryptography.
#keys /etc/ntp/keys

# Specify the key identifiers which are trusted.
#trustedkey 4 8 42

# Specify the key identifier to use with the ntpdc utility.
#requestkey 8

# Specify the key identifier to use with the ntpq utility.
#controlkey 8
#server web.icfre.org
#restrict 172.16.0.0 mask 255.255.0.0 nomodify notrap noquery
#restrict default ignore
 
Old 12-05-2011, 02:27 AM   #6
corp769
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Looks good.... On your clients, do the following:

Edit /etc/ntp/step-tickers and replace with your local NTP server.
Edit /etc/ntp/ntpservers and once again, replace with your NTP server.
Restart your NTP services, and try again.

I'm having you do this to rule out the possibility that your configurations got either messed up, or something else. At least try this on one client, and let me know if this changes anything.
 
Old 12-05-2011, 03:44 AM   #7
Satyaveer Arya
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I did the same as you suggested, but no result.

And actually I consulted my senior and he told me that on server stratum is going too high at 16, which should be atleast 10. Is there any problem of stratum on server?
 
Old 12-05-2011, 03:48 AM   #8
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Hmm... Have you tried restarting your NTP service on the server? I would also do a port scan of your server, and even telnet to it to see if you can properly connect. As far as what your senior said, how many servers and clients do you have on your network?
 
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Old 12-05-2011, 03:58 AM   #9
Satyaveer Arya
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Yes I restarted the ntp service also.

Actually what the thing is we have setup NTP Server on Web Server and all other clients are also servers. So, I was synchronizing time on my all other client servers and keep on doing that by mistake I run the ntpdate command on ntp server also and restarted the service, through which I got this whole problem.

And there are total 10 Linux servers in my organisation.
 
Old 12-06-2011, 12:43 AM   #10
Satyaveer Arya
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Friends, the problem is solved now. I'm marking it solved and closing.
 
Old 12-06-2011, 06:14 AM   #11
corp769
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Oops, I didn't see the notification.... What was the final issue?
 
Old 12-07-2011, 01:30 AM   #12
Satyaveer Arya
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The prolem was in /etc/ntp/ntpservers file, one of my colleague in his night shift had commented the entry of local time server, which I came to know later.

Last edited by Satyaveer Arya; 12-07-2011 at 01:31 AM.
 
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Old 12-07-2011, 09:35 AM   #13
corp769
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Nice... Well glad you got everything figured out!

Cheers,

Josh
 
Old 12-07-2011, 11:38 PM   #14
Satyaveer Arya
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Thanks a lot for your help.
 
  


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