NTP Server Modification

Hi There,
I am having on DC & ADC both are virtual machines and configured on HYPER -V environment.
Now during the time of implementation DC is made as the NTP server for the entire domain.
Now i need to check the configuration of NTP Server and needs to change the time setting in that.
Regards, Ravi Kumar

Hi,
In order to query or change windows time settings we can use w32tm tool.
Configure the Windows Time service on the PDC emulator in the Forest Root Domain
http://technet.microsoft.com/en-us/library/cc786897(v=ws.10).aspx
Hope this helps.

Similar Messages

Help with connecting to NIST NTP server on port 123

I can get NIST time in Daytime format using the rt_nist_date_time.llb example posted on ni.com, but I cannot connect to NIST NTP format time data using port 123. I freely admit to being over my head with this stuff, and have spent much of this Thanksgiving holiday reading about UDP and TCP.
The attached vi summarizes what I've tried so far. The UDP case is what I thought would work, but I can't come up with a network address that the UDP-open vi likes. Can anyone out there help this n00b tell the time?
The attached file is supposed to be in 8.0 format, although I'm working in 9.0
Here is a link discussing the time formats: http://tf.nist.gov/service/its.htm
Jeff
Solved!
Go to Solution.
Attachments:
UDP.vi ‏17 KB

jstevens wrote:
THANK YOU!!! I don't think I ever would have come up with connecting the web address to a Read or Write UDP rather than the Open UDP block. Not to mention starting by opening port zero.
Unlike TCP, UDP is a connectionless protocol. Here's a quick explanation in different words.
A udp packet travels from a [sourceIP, sourcePort] to a [DestinationIP, destinationPort].
UDP open basically reserves a local port used for sending (soucePort) and receiving (incoming packet with that same destinationPort). Since some local ports are always in use, you would generate an error if you would accidentally pick a used port. Picking zero is useful for requests (as in this case!), because the OS will pick an unused ephemeral port. The actual source port number does not matter because the NTP server will just send the reply packet back to whatever port it came from. (If you would write your own NTP server in LabVIEW, you would of course need to set the local port to 123, and would get a conflict if another NTP server is already running on your rig). Writing an NTP server in LabVIEW would be a trivial modification to the current code, try it! . Simply listen for packets on port 123, form a response packet based on the timestamp, and send it to whatever IP/Port it came from (that info is available from udp read) and then go back to listen for new requests.).
UDP write sends a packet to the server using the above opened local port as source port. You can use the same connectionID to write to several other servers and ports, because UDP is connectionless. (TCP is connection based, so a TCP connection involves a defined source/destination pair)
UDP read listens for incoming packets from all over the world at that same local port. It is very unlikely, but theoretically possible that other UDP packets will arrive at that same port, so you could even filter to make sure to read incoming packets until they match the port and IP of the original request. The current code is somewhat vulnerable to a DOS (denial of service) attack for example as follows: Imagine the guy in the next cubicle had means of sniffing your network traffic. He could write a small program that looks for your NTP requests and then immediately starts flooding your IP with meaningless UDP packets to the sourcePort you just used. The current program only reads one packet and thus will never see the return packet from the NTP server.
UDP close frees up the local port and the computer is now no longer listening for packets on that port. Of course you could keep the port open for the duration of the program, especially if you intend to send UDP request once in a while during execution.
Makes sense?
LabVIEW Champion . Do more with less code and in less time .

How to sync clock of Cisco ASA 5505 from NTP Server on internet

Hi there!
i've setup a site, with cisco ASA 5505. It has public ip also.
i want to sync the clock of firewall from on ntp server on internet, or with internal domain controller that is inside LAN.
The firewall has public IP also.
how can i do this?
Regards!

Hello Lasandro,
This should do it!
http://www.cisco.com/en/US/docs/security/asa/asa84/configuration/guide/basic_hostname_pw.html#wp1236530
Looking for some Networking Assistance?
Contact me directly at [email protected]
I will fix your problem ASAP.
Cheers,
Julio Carvajal Segura
http://laguiadelnetworking.com

Connecting to an NTP server

Good Afternoon.
I'm having a big problem connecting to an NTP server like www.worldTimeServer.com. I want to create a java application that can load time from such servers then display it in my time text field. I do not know how to start.
Can somebody teach me how to do it or give me a link that provides how-tos to do this.

There is a package provided by http://jakarta.apache.org/commons/net/
that have classes for ntp. I myself is new to this (very old) protocol but I'm
building an application that is needing this service so if
you find it helpful let me know.
Message was edited by:
gbohne

ASA5500 using Windows 7 computer as NTP server

I have an ASA5510 connected to a computer running Windows 7 (the NTP Server) on its "inside" interface.
Using the ASDM, I have configured the ASA5510 to use the Windows 7 as its NTP server (my architecture forces me to use a local machine as an NTP server):
     -IP address: 192.0.99.1 (the ASA5510 has an IP address of 192.0.99.40)
     -Interface: inside
     -Key number: None
     -Enable NTP authentication: no.
I have other Windows computers on the "inside" interface using the NTP Server, so NTP traffic is relayed without any problem. But somehow, the ASA5510 is not able to synchronize with the NTP Server.
I see the following log entry:
     -Source IP: 192.0.99.1
     -Source Port: 123
     -Destination IP: 192.0.99.40
     -Destination port: 65535
     -Description: Teardown UDP connection 3905 for inside: 192.0.99.1/123 to identity: 192.0.99.40/65535 duration 0:02:01 bytes 96
so it seems like the ASA5510 sends a request to the NTP Server, but I am not sure whether the reply doesn't get processed correctly, or the connection stays open too long (my UDP connection timeout is the default, 2 minutes).
I had trouble getting SonicWALL NSA2400s to use Windows 7 devices as NTP servers. I had to get a firmware version where there was no MD5 authentication (which I think is OK in this case), and change a setting in the Windows registry (HKEY_LOCAL_MACHINE/SYSTEM/CurrentControlSet/services/W32Time/Config/AnnounceFlags: from 0xa to 0x5)
any insight is welcome.
Pedro

I have turned on all ntp debugging, and run "show ntp status" and "show ntp assoc":
CCG-SHIP-FWL(config)# show debug
debug ntp adjust enabled at level 1
debug ntp authentication enabled at level 1
debug ntp events enabled at level 1
debug ntp packets enabled at level 1
debug ntp params enabled at level 1
debug ntp select enabled at level 1
debug ntp sync enabled at level 1
debug ntp validity enabled at level 1
CCG-SHIP-FWL(config)# show ntp status
Clock is unsynchronized, stratum 16, no reference clock
nominal freq is 99.9984 Hz, actual freq is 99.9984 Hz, precision is 2**6
reference time is 00000000.00000000 (06:28:16.000 GMT Thu Feb 7 2036)
clock offset is 0.0000 msec, root delay is 0.00 msec
root dispersion is 0.00 msec, peer dispersion is 0.00 msec
CCG-SHIP-FWL(config)# show ntp assoc
      address         ref clock     st when poll reach delay offset    disp
~192.16.99.1      .LOCL.            1   380 1024 337    73.0 255671    71.0
* master (synced), # master (unsynced), + selected, - candidate, ~ configured
CCG-SHIP-FWL(config)# NTP: xmit packet to 192.16.99.1:
leap 3, mode 3, version 3, stratum 0, ppoll 1024
rtdel 0000 (0.000), rtdsp 10400 (1015.625), refid 00000000 (0.0.0.0)
ref 00000000.00000000 (06:28:16.000 GMT Thu Feb 7 2036)
org d34ac42f.4609d99d (20:21:03.273 GMT Tue May 1 2012)
rec d34a6050.3598360c (13:14:56.209 GMT Tue May 1 2012)
xmt d34a6250.22e73ba2 (13:23:28.136 GMT Tue May 1 2012)
NTP: rcv packet from 192.16.99.1 to OWN_FWL_LAN_PORT on inside:
leap 0, mode 4, version 3, stratum 1, ppoll 1024
rtdel 0000 (0.000), rtdsp a0bf4 (10046.692), refid 4c4f434c (76.79.67.76)
ref d34abbb0.bb426e39 (19:44:48.731 GMT Tue May 1 2012)
org d34a6250.22e73ba2 (13:23:28.136 GMT Tue May 1 2012)
rec d34ac62f.3977adb6 (20:29:35.224 GMT Tue May 1 2012)
xmt d34ac62f.3977adb6 (20:29:35.224 GMT Tue May 1 2012)
inp d34a6250.233258a0 (13:23:28.137 GMT Tue May 1 2012)
NTP: nlist 0, allow 0, found 0, low 0.000000, high 0.000000
NTP: no select intersection
NTP: synchronization lost

Xntpd on Solaris 10 gets synchronised with a higher stratum NTP server

The Solaris 10 machine has the following configuration in etc/inet/ntp.conf
server 10.24.179.33 prefer
server 127.127.1.0
fudge 127.127.1.0 stratum 8
The Linux Fedora Core 4 test machine(10.24.179.33 ) configured as NTP server running ntpd V4 has the following configuration
server 127.127.1.0
fudge 127.127.1.0 stratum 10
The solaris 10 xntpd get synchronised to Linux NTP server even though it is at a higher stratum level.
# ntpq -p
remote refid st t when poll reach delay offset disp
==============================================================================
*10.24.179.33 LOCAL(0) 11 u 18 64 77 2.04 0.084 376.68
LOCAL(0) LOCAL(0) 8 l 17 64 77 0.00 0.000 385.01
The expectation was the solaris machine should not consider the server at a higher stratum level(11) for synchronistation. It should have got synchronised to the Local clock which is at stratum level 8.

I now tried waiting for an hour, but the xntpd id still synchronised to the higher stratum clock from the NTP server 10.24.179.33. Please verify the logs below.
Does the prefer keyword in line "server 10.24.179.33 prefer" has anything to do with this behaviour ?
What does the RFC1305 say on process of selecting a synchronisation source ?
My understanding was that xntpd should not be synchornising with a higher stratum clock from the NTP server (which is at stratum 11) when it already has as another server(here the local clock) which is at a lower stratum (we have simulated this by fudging the local clock to stratum 8).
Please correct me on this.
You have mentioned that "Stratum number is not absolute for choosing a clock. A higher stratum may be preferred in some situations."
Could you explain me more on these situations and I also want to know the rules used by xntpd to choose a clock?
Or you could provide any links where I can read more on this aspect.
# ntpq -p
remote refid st t when poll reach delay offset disp
==============================================================================
10.24.179.33 LOCAL(0) 11 u 13 64 1 0.52 -0.001 15875.0
LOCAL(0) LOCAL(0) 8 l 12 64 1 0.00 0.000 15885.0
(WCCONGO02):(root) UTC 1:21:37 VER R-02.01.16.03
# ntpq -p
remote refid st t when poll reach delay offset disp
==============================================================================
*10.24.179.33 LOCAL(0) 11 u 1 64 77 0.52 -0.244 376.77
LOCAL(0) LOCAL(0) 8 l 64 64 37 0.00 0.000 885.01
(WCCONGO02):(root) UTC 1:26:45 VER R-02.01.16.03
# uname -a
SunOS WCCONGO02 5.10 Generic_127127-11 sun4v sparc SUNW,Netra-T5440
(WCCONGO02):(root) UTC 1:29:44 VER R-02.01.16.03
# ntpq -p
remote refid st t when poll reach delay offset disp
==============================================================================
*10.24.179.33 LOCAL(0) 11 u 40 64 377 0.61 0.415 0.56
LOCAL(0) LOCAL(0) 8 l 39 64 377 0.00 0.000 10.01
(WCCONGO02):(root) UTC 2:7:56 VER R-02.01.16.03
# ntpq -p
remote refid st t when poll reach delay offset disp
==============================================================================
*10.24.179.33 LOCAL(0) 11 u 13 64 377 2.26 1.289 0.66
LOCAL(0) LOCAL(0) 8 l 12 64 377 0.00 0.000 10.01
(WCCONGO02):(root) UTC 2:22:25 VER R-02.01.16.03
Edited by: SujithKS on May 27, 2009 10:34 AM
Edited by: SujithKS on May 27, 2009 11:26 AM

"Local" failover for NTP Server on Solaris 10

I have four Solaris 10 Servers, all syncing their time from an external NTP server ntp.example.com.
Is it possible to configure one of the four servers as a local "pseudo" Failover NTP, i.e. acting as a client to ntp.example.com, as long as it is available, and acting as a NTP server to the remaining three servers in case ntp.example.com is not available, so that at least the four local servers remain synced among themselves?

Shouldn't be any problem. For one thing you can always specify multiple servers in the /etc/inet/ntp.conf file and use one of them as 'prefer', i.e.:
server ntp.example.com prefer
server local.mydomain.com
Then again, perhaps it would just be easier if one of your servers syncs against 'ntp.example.com' and the rest of your servers always synchronizes against that one server?
.7/M.

Problem synchronizing windows clients with solaris 10 NTP server

Hello everyone,
I realyy need help on the following:
I tried to synchronize windows 2003 as client with NTP server running in Solaris 10
My Time Zone in the NTP server is GMT+3, and in my windows is also set to GMT+3
When I start NTP server and clients , I got 6 hours delay between the clients and the server
I tried to synchronize the Solaris server with another solaris system, the synchronization is working fine
Your help
Regards
Hakim Fourar

True (but only for later releases). But since he mentioned getting a 6 hour offset after starting them, that makes me think that the systems are communicating, and that the time zones are incorrect.
This is easily verified by using 'ntpq -p' and 'date ; date -u'. The first will show if the client thinks it is synchronized to a server (and what the UTC offset is in miliseconds). The second will show the date in the default timezone and in UTC.
If you're not using POSIX, you'd think that GMT+XX meant east of UTC, but for POSIX, it means west of UTC.
Darren

NTP server setup in DMZ

Hi Team,
We have Windows 2008 AD infrastructure with Single domain Single Forest & 30 remote AD sites with RODC in it.
We are planning for NTP server setup on Windows 2008 server in DMZ......can someone help me with steps for setup.
What is best practice for NTP architecture so that all DC will sync time from NTP & NTP sync time from external source.
Please suggest.

Hi,
Would you please tell us that has the plan of your security team worked out?
Because based on what I understand, domain members will synchronize time from Domain Controllers while DCs will synchronize time from PDC.
Here is a thread below about the best practices of time synchronization in a domain:
Time Sync best practices
http://social.technet.microsoft.com/Forums/windowsserver/en-US/043b1ebe-e7bc-40ca-91e0-174a6854808e/time-sync-best-practices?forum=winserverDS
Best Regards,
Amy

NTP Server IP Address ?

Hi,
I have configured a Cisco 6509 core switch as a NTP master and allowed all my access switches to get their time synchronised with the core switch. Now, I want to configure the core switch to get itself synchronised with other public NTP server which would be reliable and genuine as our organisation is serving for healthcare. One of my friend has told me to use these IPs 128.249.1.1 or 128.2.136.71 as a NTP Server in the core switch. Should I use them?
Is Cisco recommends any Public IP for NTP Server synchronisation? Please suggest.
Thanks & Regards,
Anil K.

Disclaimer: I have no affiliation with Cisco in any way except where I work, we use some Cisco products (sw/hw). So take it however you will.
Personally, I would rather adopt the following approach suggested at http://www.pool.ntp.org/en/use.html, than hardcoding a couple of public NTP servers in a remote region:
"As pool.ntp.org will assign you timeservers from all over the world, time quality will not be ideal. You get a bit better result if you use the continental zones (For example europe, north-america, oceania or asia.pool.ntp.org), and even better time if you use the country zone (like ch.pool.ntp.org in Switzerland) - for all these zones, you can again use the 0, 1 or 2 prefixes, like 0.ch.pool.ntp.org. Note, however, that the country zone might not exist for your country, or might contain only one or two timeservers. If you know timeservers that are really close to you (measured by network distance, with traceroute or ping), time probably will be even better. "
Of course, if time sync is REALLY that important, one might consider buying/installing commercial GPS-based NTP appliances. That's not what you're looking for, obviously.

Synchronize with External NTP server.

Dear All Good morning,
Environment:
SunOS CSF-2 5.10 Generic_138888-03 sun4u sparc SUNW, Sun-Fire-V245 system.
Sun Cluster 3-2 Two node.
Question:
How to Synchronize Cluster timing with external NTP server/device? If external NTP device is down will have any impact in the cluster setup?

epmuneer wrote:
Question:
How to Synchronize Cluster timing with external NTP server/device?The configuration for NTP on Solaris Cluster is explained here:
[http://docs.sun.com/app/docs/doc/820-4676/cacbdgeg?l=en&a=view|http://docs.sun.com/app/docs/doc/820-4676/cacbdgeg?l=en&a=view]
and
[http://docs.sun.com/app/docs/doc/820-4677/cbhijhbh?l=en&a=view|http://docs.sun.com/app/docs/doc/820-4677/cbhijhbh?l=en&a=view]
If external NTP device is down will have any impact in the cluster setup?You should configure the cluster nodes as peers as well as getting the time from the external NTP server.
If the external NTP server fails, then time will drift, but at least the cluster nodes keep themselves in sync to have a consistent view.
Regards
Thorsten

W32tm always on "Local CMOS clock" on virtual domain controller - cannot change to NTP server

The domain controller (Server 2012R2) is hosted on Hyper-V (Server 2012R2). It is a PDC.
- firewall disabled
- cleaned up w32tm:
net stop w32time
w32tm /unregister
w32tm /register
net start w32time
- applied ifixit from http://support.microsoft.com/kb/816042 to enable external ntp server de.pool.ntp.org
- disabled
VMICTimeProvider in registry
(HKLM\SYSTEM\CurrentControlSet\Services\W32Time\TimeProviders\VMICTimeProvider\Enabled = 0)
I can manually query the ntp server de.pool.ntp.org:
w32tm /stripchart /computer:de.pool.ntp.org /samples:5 /dataonly
de.pool.ntp.org wird verfolgt [131.188.3.221:123].
5 Proben werden gesammelt.
Es ist 24.04.2014 10:07:36.
10:07:36, +00.0115379s
10:07:38, -00.0025048s
10:07:40, -00.0008595s
10:07:42, -00.0010477s
10:07:44, -00.0014516s
But still, w32tm does NOT query the ntp server:
PS C:\Windows\system32> w32tm /query /source
Local CMOS clock
rosch

Hi rosch,
Based on your description, please check if disable the "Time synchronization" Integration service. Please refer
to the following operation.
In Hyper-V Manager, right click the DC and select “Settings…”.
In the left panel of Settings, navigate to Integration Services and click it.
Then in the right panel, please uncheck Time synchronization.
By the way, please check if can connect to the time server and UDP port was opened for NTP.
If any update, please feel free to let me know.
Hope this helps.
Best regards,
Justin Gu

CER 7.1.1 install - no NTP server option

Trying to install CER 7.1.1. When I get to the Network Time Protocol Client Configuration window it prompts me to put in an NTP server IP address. The install never prompts me to configure an NTP server or not. The install doc says that I should get prompted to choose NTP or not, just like a CUCM install. Did I do something wrong? I tried it several times and get the same thing. I have a Not For Resale disc and this is in a lab. Is there something special about that disc? I don't want to use NTP but I configured a Win2K3 server to be the NTP server, it's reachable but the install can never connect to it. Needless to say, I can't finish the install. Below is what I get.
Network Time Protocol Client Configuration
NTP Server 1 ---------
NTP Server 2 ---------
NTP Server 3 ----------
NTP Server 4 ----------
NTP Server 5 ----------
There is no option to choose No NTP. You either have to put in an NTP server or you can't move on with the installation.

Thanks for the replies. I was using an installation guide, below, that shows the option to choose NTP or not on step 18. Is the document wrong then? In any case, I tried the hacks for Windows, no go. I tried Linux NTP {Ubuntu], no go. Otherwise, I just have a voice gateway and a 3524 that doesn't do NTP server. Any suggestions on getting Linux to work with CER NTP? Thanks.
Step 18 On the Network Time Protocol Client Configuration page, you are asked if you want to set up external Network Time Protocol (NTP) servers.
Note Cisco strongly recommends that you use external NTP servers to ensure that the system time is kept accurate.
If you click Yes, the system displays a second Network Time Protocol Client Configuration page. In the fields provided, enter the IP address or hostname of the external NTP servers, then click OK. The Database Access Security Configuration page displays. Skip to Step 19.
If you click No, the Hardware Clock Configuration page appears. Enter the following information:
• Year [yyyy]
• Month [mm]
• Day [dd]
• Hour [hh]
• Minute [mm]
• Second [ss]
When you have finished entering this information, click OK. The Database Access Security Configuration page appears.
http://www.cisco.com/en/US/docs/voice_ip_comm/cer/7_0/english/administration/guide/e911inst.html

NTP server - can't fix it

Hello,
I have two 10.6.4 server machines wich I use as NTP server for my clients (both referes to time.europe.apple.com and have flagged NTP under general settings to enable NTP).
One of them works properly: if on a client i use his FQDN or IP they took istantly the right hour.. the other one is like unseen from clients.
both of them have the following files configurations:
/private/etc/ntp.conf
server time.euro.apple.com
/private/etc/ntp-restrict.conf
restrict default kod nomodify notrap nopeer noquery
restrict -6 default kod nomodify notrap nopeer noquery
#localhost is unrestricted
restrict 127.0.0.1
restrict -6 ::1
includefile /private/etc/ntp.conf
I can figure out why one of them works and the other one not..
Both of them have firewall service off.

Maybe if you tried to restore your computer back to a month ago or sometime before you had this problem?

Anyone got NTP working with a Windows 2008 NTP server?

Hello,
I'm trying to sync the time on our routers and swithces with a Windows 2008R2 server, but it doesn't work. Has anyone managed to do this:
Config:
ntp master
ntp update-calendar
ntp server 192.168.2.164
sh ntp associations
address         ref clock         st   when   poll   reach    delay    offset     disp
*~127.127.1.1     .LOCL.         7     11     16      377      0.000   0.000      0.225
~192.168.2.164 .INIT.          16      -      1024     0       0.000    0.000    15937.
Windows 2008R2 server
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\W32Time\TimeProviders\NtpServer]"
"Enabled"=dword:00000001
restart server
w32tm /config /manualpeerlist:uk.pool.ntp.org,0x8 /syncfromflags:MANUAL
net stop w32time
net start w32time
Doesnt work
Woudl Linux like Ubuntu be better?
Thanks

I got this working from a cisco 2911 router to Windows 7 computer.
As per many articles, you are missing:-
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\W32Time\Config]"
"AnnounceFlags"=dword:00000005
But the one that allows Cisco kit to Sync is:-
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\W32Time\Config]"
"LocalClockDispersion"=dword:00000000
This article http://www.cisco.com/c/en/us/support/docs/ip/network-time-protocol-ntp/108076-ntp-troubleshoot.html talks about having a root-dispersion higher than 1000ms (1 second) causing Cisco IOS-NTP to unsynchronizes itself.
This article http://htluo.blogspot.co.uk/2009/02/ntp-network-time-protocol.html#comment-form was the only one I found that added to the normal enable ntp server registry keys information, stating to change ‘HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\W32Time\Config\LocalClockDispersion’ from 10 to 0
There was also articles that said that the Windows NTP implementation was version 3, and therefore you had to append ‘version 3’ to the routers ‘ntp server x.x.x.x’ command. This may be perhaps true for earlier windows versions?, but was NOT required for Windows 7.

NTP Server Modification

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