I have a Centos 5 64-bit server that has ntp service enabled. Windows XP with SP2 cannot properly sync to it for time, but can communicate with it via samba, ssh, and anything else. I also disabled the Windows Firewall. The C5 system does not have any firewall enabled.
Other C5 workstations can successfully sync to it via ntpdate.
What else could cause the XP machine to not be able to time sync with the C5 server?
Thanks.
Scott
XP command line:
net time \servername returns what?
Perhaps the response will give a clue.
To set it:
net time \servername /set /yes
-----Original Message----- From: centos-bounces@centos.org [mailto:centos-bounces@centos.org] On Behalf Of Scott Ehrlich Sent: Friday, February 01, 2008 11:37 AM To: centos@centos.org Subject: [CentOS] NTP server
I have a Centos 5 64-bit server that has ntp service enabled. Windows XP with SP2 cannot properly sync to it for time, but can communicate with it via samba, ssh, and anything else. I also disabled the Windows Firewall. The C5 system does not have any firewall enabled.
Other C5 workstations can successfully sync to it via ntpdate.
What else could cause the XP machine to not be able to time sync with the C5 server?
Thanks.
Scott _______________________________________________ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
on 2/1/2008 12:03 PM Dennis McLeod spake the following:
XP command line:
net time \servername returns what?
Perhaps the response will give a clue.
To set it:
net time \servername /set /yes
Net time is only used to set time from a domain controller, not an ntp server. They use two completely different protocols.
Scott Silva wrote:
on 2/1/2008 12:03 PM Dennis McLeod spake the following:
XP command line:
net time \servername returns what?
Perhaps the response will give a clue.
To set it:
net time \servername /set /yes
Net time is only used to set time from a domain controller, not an ntp server. They use two completely different protocols.
however,
NET TIME /SETSNTP:ip-of-ntp-server
WILL set the windows 'internet time' server IP.
NET TIME /QUERYSNTP
will show the current 'internet time' server(s).
note that the default Windows NTP client is really braindead, it just 'sets' the system clock once a day, its not a proper NTP implementation. for most users, this is fine, but realize oddities can happen like the clock being set back a few seconds such that a given time happens twice.
On Fri, 2008-02-01 at 13:29 -0800, John R Pierce wrote:
Scott Silva wrote:
on 2/1/2008 12:03 PM Dennis McLeod spake the following:
XP command line:
net time \servername returns what?
Perhaps the response will give a clue.
To set it:
net time \servername /set /yes
Net time is only used to set time from a domain controller, not an ntp server. They use two completely different protocols.
however,
NET TIME /SETSNTP:ip-of-ntp-serverWILL set the windows 'internet time' server IP.
NET TIME /QUERYSNTPwill show the current 'internet time' server(s).
note that the default Windows NTP client is really braindead, it just 'sets' the system clock once a day, its not a proper NTP implementation. for most users, this is fine, but realize oddities can happen like the clock being set back a few seconds such that a given time happens twice.
Very true.
You can modify the time interval by editing your registry.
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\W32Time \TimeProviders\NtpClient]
"SpecialPollInterval"=dword:00001c20
This will set it to update every two hours. The dword can be modified to set it for 1 hour to whatever.
-jason
on 2/1/2008 1:29 PM John R Pierce spake the following:
Scott Silva wrote:
on 2/1/2008 12:03 PM Dennis McLeod spake the following:
XP command line:
net time \servername returns what?
Perhaps the response will give a clue.
To set it:
net time \servername /set /yes
Net time is only used to set time from a domain controller, not an ntp server. They use two completely different protocols.
however,
NET TIME /SETSNTP:ip-of-ntp-server
WILL set the windows 'internet time' server IP.
NET TIME /QUERYSNTP
will show the current 'internet time' server(s).
note that the default Windows NTP client is really braindead, it just 'sets' the system clock once a day, its not a proper NTP implementation. for most users, this is fine, but realize oddities can happen like the clock being set back a few seconds such that a given time happens twice.
I stand partially corrected, as the originally posted command line of "net time \servername /set /yes" would not query a ntp server.
Scott Ehrlich wrote:
I have a Centos 5 64-bit server that has ntp service enabled. Windows XP with SP2 cannot properly sync to it for time, but can communicate with it via samba, ssh, and anything else. I also disabled the Windows Firewall. The C5 system does not have any firewall enabled.
The following would stop this:
1) DNS with a fully qualified name. 2) CentOS-5 server does not have port 123 open on its firewall iptables -nxvL | grep 123
should give you an answer to that 3) CentOS-5 server is not serving NTP to your network
netstat -nalp | grep :123
should have something other than udp 0 0 127.0.0.1:123 0.0.0.0:*
This is configured in the /etc/ntp.conf file.
Scott Ehrlich schrieb:
I have a Centos 5 64-bit server that has ntp service enabled. Windows XP with SP2 cannot properly sync to it for time, but can communicate with it via samba, ssh, and anything else. I also disabled the Windows Firewall. The C5 system does not have any firewall enabled.
Other C5 workstations can successfully sync to it via ntpdate.
What else could cause the XP machine to not be able to time sync with the C5 server?
I'd double-check the c5 ntpd config. Are the xp machines really in the same allowed subnet like the c5 workstations?
Personally I don't use Windows' time sync anymore, I use the ntp implementation for windows from here:
http://www.meinberg.de/english/sw/ntp.htm
Install/config is very easy, you even get the ntpdc command.
Rainer
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Dennis McLeod -
Jason Ross -
John R Pierce -
Rainer Traut -
Scott Ehrlich -
Scott Silva -
Stephen John Smoogen