server is not getting synchronized with ntp server

mannam_srinivas · June 11, 2009, 8:00am

Hello Guys,

i have a problem my local server is not getting synchronized with ntpd server.

1)ntpq -p is giving the following output

remote refid st t when poll reach delay offset jitter

==============================================================================

ntp1 0.0.0.0 16 u - 64 0 0.000 0.000 4000.00

ntp2 0.0.0.0 16 u - 64 0 0.000 0.000 4000.00

(i)i know that if there is no * mark in front of any ntp server means no ntp server is running is my understanding correct?

(ii)in the above output of ntpq -p what is the significance of refid and it's value here is 0.0.0.0 can some body explain this?

2) while i am trying to restart ntps service it's failing and saying the following message

service ntpd start

ntpd: Synchronizing with time server: [FAILED]

Starting ntpd: [ OK ]

3) here i am pasting the /etc/ntp.conf file

vi /etc/ntp.conf

# Prohibit general access to this service.

driftfile /var/lib/ntp/drift

restrict 127.0.0.1

restrict 132.95.160.58 nomodify notrap noquery

restrict 132.95.160.127 nomodify notrap noquery

server ntp1 version 3

server ntp2 version 3

restrict default ignore

# Permit all access over the loopback interface. This could

# be tightened as well, but to do so would effect some of

# the administrative functions.

# -- CLIENT NETWORK -------

# Permit systems on this network to synchronize with this

# time service. Do not permit those systems to modify the

# configuration of this service. Also, do not use those

# systems as peers for synchronization.

# restrict 192.168.1.0 mask 255.255.255.0 notrust nomodify notrap

# --- OUR TIMESERVERS -----

# or remove the default restrict line

# Permit time synchronization with our time source, but do not

# permit the source to query or modify the service on this system.

# restrict mytrustedtimeserverip mask 255.255.255.255 nomodify notrap noquery

# server mytrustedtimeserverip

# --- NTP MULTICASTCLIENT ---

#multicastclient # listen on default 224.0.1.1

# restrict 224.0.1.1 mask 255.255.255.255 notrust nomodify notrap

# restrict 192.168.1.0 mask 255.255.255.0 notrust nomodify notrap

# --- GENERAL CONFIGURATION ---

#

# Undisciplined Local Clock. This is a fake driver intended for backup

# and when no outside source of synchronized time is available. The

# default stratum is usually 3, but in this case we elect to use stratum

# 0. Since the server line does not have the prefer keyword, this driver

# is never used for synchronization, unless no other other

# synchronization source is available. In case the local host is

# controlled by some external source, such as an external oscillator or

# another protocol, the prefer keyword would cause the local host to

# disregard all other synchronization sources, unless the kernel

(i)in the above ntp.conf file i found the following lines are these correct

132.95.160.58 and 132.95.160.127 are ntp servers we are using

restrict 132.95.160.58 nomodify notrap noquery

restrict 132.95.160.127 nomodify notrap noquery

4) pls also find ntpdate -d (ntp server )

ntpdate -d 132.95.160.58

11 Jun 14:43:38 ntpdate[12230]: ntpdate 4.1.2@1.892 Tue Feb 24 06:32:26 EST 2004 (1)

transmit(132.95.160.58)

132.95.160.58: Server dropped: no data

server 132.95.160.58, port 123

stratum 0, precision 0, leap 00, trust 000

refid [0.0.0.0], 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: cddb261d.f2249a13 Thu, Jun 11 2009 14:43:41.945

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

11 Jun 14:43:42 ntpdate[12230]: no server suitable for synchronization found

5) drift file from /var/lib/ntp/drift

82.107

is it compulsory drift value always should be 0 if it's so how can we change here this value to 0.

kindly check this and provide your valuable feedback why ntp server is not synchronizing with my server.

with regards,
Srinu

DukeNuke2 · June 11, 2009, 8:23am

what does a "ping ntp1" or "ping ntp2" returns on your system?

mannam_srinivas · June 11, 2009, 8:52am

here we are using only ntp1 and ntp2 is not in use

while pinging npt1 we foound the following output

ping 132.95.160.58

PING 132.95.160.58 (132.95.160.58) 56(84) bytes of data.

--- 132.95.160.58 ping statistics ---

78 packets transmitted, 0 received, 100% packet loss, time 77379ms

wew found that pinging from my local server to ntp server is inhibited that's why we are getting 100% packet loss .

with the same ntp server we had another local server running fine without problems in ntp server there also we found pinging is inhibited

ping 132.95.160.58
PING 132.95.160.58 (132.95.160.58) 56(84) bytes of data.
--- 132.95.160.58 ping statistics ---
10 packets transmitted, 0 received, 100% packet loss, time 9044ms

DukeNuke2 · June 11, 2009, 8:54am

so, solve the network problem and ntp should run fine...

mannam_srinivas · June 11, 2009, 8:59am

hi
here from my local server to ntp server pinging is inhibited that's why we observed 100% packet loss but another local server with 100% packet loss is able to sync with ntp server

i beleive it's not a network problem if it's network problem another local server also should not get synced with ntp server where also we observed 100% packet loss right?
if my understanding is not correct could u pls eaplain it.

thank you

Srinu

DukeNuke2 · June 11, 2009, 9:01am

if you can't reach the ntp server over your network, how can you get it synced? what is the "ntpq -p" output from the other server?

mannam_srinivas · June 11, 2009, 9:10am

Hi

i will provide the ouput of command ntpq -p after some time

here i am pasting ntpdate -d server command output from my local server where my local server is getting synced with ntp servere

ntpdate -d 132.95.160.58
11 Jun 14:55:24 ntpdate[28190]: ntpdate 4.1.2@1.892 Tue Feb 24 06:32:26 EST 2004 (1)
transmit(132.95.160.58)
receive(132.95.160.58)
transmit(132.95.160.58)
receive(132.95.160.58)
transmit(132.95.160.58)
receive(132.95.160.58)
transmit(132.95.160.58)
receive(132.95.160.58)
transmit(132.95.160.58)
server 132.95.160.58, port 123
stratum 1, precision -20, leap 00, trust 000
refid [GPS ], delay 0.03345, dispersion 0.00006
transmitted 4, in filter 4
reference time: cddb28db.00000000 Thu, Jun 11 2009 14:55:23.000
originate timestamp: cddb28dc.8fc18000 Thu, Jun 11 2009 14:55:24.561
transmit timestamp: cddb28dc.8e9435ac Thu, Jun 11 2009 14:55:24.556
filter delay: 0.03375 0.03371 0.03345 0.03372
0.00000 0.00000 0.00000 0.00000
filter offset: 0.000585 0.000518 0.000445 0.000543
0.000000 0.000000 0.000000 0.000000
delay 0.03345, dispersion 0.00006
offset 0.000445
11 Jun 14:55:24 ntpdate[28190]: adjust time server 132.95.160.58 offset 0.000445 sec

kindly check it and provide u r feedback.

regards,
Srinu

DukeNuke2 · June 11, 2009, 9:24am

i don't know whats goin on there but i would vote for a network problem...

mannam_srinivas · June 12, 2009, 1:53am

hi pls find the pasted ntpq -pn output where local server is getting synced with ntp server
[root@eabs-a root]# ntpq -pn
remote refid st t when poll reach delay offset jitter