# Client Configuration and Development **URL:** https://community.ntppool.org/c/clients/10.md [Latest](https://community.ntppool.org/latest.md) · [Categories](https://community.ntppool.org/categories.md) · [Tags](https://community.ntppool.org/tags.md) --- ## [About the Client Configuration and Development category](https://community.ntppool.org/t/about-the-client-configuration-and-development-category/755)
**Author:** [@ask](https://community.ntppool.org/u/ask)\ **Replies:** 0
--- ## [Who watches the watchers?](https://community.ntppool.org/t/who-watches-the-watchers/4164)
**Author:** [@elvisimprsntr](https://community.ntppool.org/u/elvisimprsntr)\ **Replies:** 14\ **Last updated:** [September 22, 2026, 2:52pm UTC](https://community.ntppool.org/t/who-watches-the-watchers/4164 "2026-09-22T14:52:21Z")
BACKGROUND My GPS+PPS disciplined NTP server is being monitored by the pool. I read ntppool uses SNTP for monitoring, which does not take into account asymmetric latencies, but I was curious to know why some can… --- ## [Oracle Linux vendor zone: request for a clear decision and a usable vendor-zone process](https://community.ntppool.org/t/oracle-linux-vendor-zone-request-for-a-clear-decision-and-a-usable-vendor-zone-process/4503)
**Author:** [@Mr.Tao](https://community.ntppool.org/u/Mr.Tao)\ **Replies:** 11\ **Last updated:** [August 14, 2026, 9:56am UTC](https://community.ntppool.org/t/oracle-linux-vendor-zone-request-for-a-clear-decision-and-a-usable-vendor-zone-process/4503 "2026-08-14T09:56:45Z")
I would like to start a new topic to summarize the long-running Oracle Linux vendor-zone request and ask for a clear way forward. This is not meant as a personal attack on anyone. I appreciate that the NTP Pool is large… --- ## [NTP Server from Pool Sending Wrong Time](https://community.ntppool.org/t/ntp-server-from-pool-sending-wrong-time/4591)
**Author:** [@ZacharyPax](https://community.ntppool.org/u/ZacharyPax)\ **Replies:** 14\ **Last updated:** [July 23, 2026, 3:04pm UTC](https://community.ntppool.org/t/ntp-server-from-pool-sending-wrong-time/4591 "2026-07-23T15:04:22Z")
Hello, I had sent an email to some email address from the project but I figured I’d also talk about it here. For the past week or so some of our endpoints have gotten horribly wrong times. Upon looking at all the NTP t… --- ## [Some NTP servers in China are experiencing issues, with their time running about five minutes behind the actual time](https://community.ntppool.org/t/some-ntp-servers-in-china-are-experiencing-issues-with-their-time-running-about-five-minutes-behind-the-actual-time/4207)
**Author:** [@Afinder](https://community.ntppool.org/u/Afinder)\ **Replies:** 5\ **Last updated:** [March 5, 2026, 2:37am UTC](https://community.ntppool.org/t/some-ntp-servers-in-china-are-experiencing-issues-with-their-time-running-about-five-minutes-behind-the-actual-time/4207 "2026-03-05T02:37:26Z")
Some NTP servers in China are experiencing issues, with their time running about five minutes behind the actual time. Can somebody tell me how and when to fix it. --- ## [NTP server on LXC container with read only for system clock](https://community.ntppool.org/t/ntp-server-on-lxc-container-with-read-only-for-system-clock/4244)
**Author:** [@freezer](https://community.ntppool.org/u/freezer)\ **Replies:** 6\ **Last updated:** [February 23, 2026, 5:38pm UTC](https://community.ntppool.org/t/ntp-server-on-lxc-container-with-read-only-for-system-clock/4244 "2026-02-23T17:38:21Z")
I have setup a GNSS steered PTP Grandmaster on my network and have my Proxmox host synced via hardware timestamping. It seems you cannot have both hardware and software at the same time, so I was figuring on setting chr… --- ## [Chrony comparison - Ubuntu vs FreeBSD](https://community.ntppool.org/t/chrony-comparison-ubuntu-vs-freebsd/4148)
**Author:** [@ccb056](https://community.ntppool.org/u/ccb056)\ **Replies:** 43\ **Last updated:** [January 17, 2026, 5:07pm UTC](https://community.ntppool.org/t/chrony-comparison-ubuntu-vs-freebsd/4148 "2026-01-17T17:07:48Z")
I noticed that on the same machine, with the same configuration, Chrony has much higher/worse estimated error and standard deviation for GPS clocks when run in Linux/Ubuntu vs FreeBSD Here are my Ubuntu stats: And h… --- ## [Hardware Compatibility List for GPS or PPS](https://community.ntppool.org/t/hardware-compatibility-list-for-gps-or-pps/1838)
**Author:** [@comperem](https://community.ntppool.org/u/comperem)\ **Replies:** 9\ **Last updated:** [November 4, 2025, 3:36pm UTC](https://community.ntppool.org/t/hardware-compatibility-list-for-gps-or-pps/1838 "2025-11-04T15:36:22Z")
Is there a Hardware Compatibility List for PPS devices or GPS units with PPS? I’m interested in a low cost GPS unit, with PPS and a USB interface. Raspberry Pis and other single board computers have a hardware GPIO int… --- ## [Tech report on S/NTP clients behavior](https://community.ntppool.org/t/tech-report-on-s-ntp-clients-behavior/4107)
**Author:** [@giovane](https://community.ntppool.org/u/giovane)\ **Replies:** 7\ **Last updated:** [October 30, 2025, 12:20pm UTC](https://community.ntppool.org/t/tech-report-on-s-ntp-clients-behavior/4107 "2025-10-30T12:20:25Z")
Folks, We’ve release a technical report on S/NTP clients behavior doing normal operations and under attack. Maybe some of you will find it interesting, and feedback is always welcome. It will also be presented today a… --- ## [FreeBSD conntrack equivalent for pfsense ntpd](https://community.ntppool.org/t/freebsd-conntrack-equivalent-for-pfsense-ntpd/3822)
**Author:** [@koehn](https://community.ntppool.org/u/koehn)\ **Replies:** 11\ **Last updated:** [August 12, 2025, 11:07am UTC](https://community.ntppool.org/t/freebsd-conntrack-equivalent-for-pfsense-ntpd/3822 "2025-08-12T11:07:50Z")
I run an NTP on a pfsense server and while it works well, the state table fills up with unneeded cruft. I know that on Linux one can use iptables to bypass the conntrack and not fill up the Linux equivalent table. Any i… --- ## [Unable to register a vendor zone](https://community.ntppool.org/t/unable-to-register-a-vendor-zone/2764)
**Author:** [@Mr.Tao](https://community.ntppool.org/u/Mr.Tao)\ **Replies:** 9\ **Last updated:** [May 30, 2025, 3:42pm UTC](https://community.ntppool.org/t/unable-to-register-a-vendor-zone/2764 "2025-05-30T15:42:48Z")
I intend to conform with the best practices described in the wiki and register a vendor zone for Oracle Linux. I went through the steps outlined there a few months ago but haven’t heard back from anybody from the NTP po… --- ## [Asymmetric latency measurement tool](https://community.ntppool.org/t/asymmetric-latency-measurement-tool/3336)
**Author:** [@Badeand](https://community.ntppool.org/u/Badeand)\ **Replies:** 18\ **Last updated:** [November 11, 2024, 6:24pm UTC](https://community.ntppool.org/t/asymmetric-latency-measurement-tool/3336 "2024-11-11T18:24:45Z")
Hello, I made a little tool (with ChatGPT doing most the actual coding work) that measures the round trip latency between two systems on the internet in each direction, detecting any asymmetry in the network latency. I’… --- ## [2.uk.pool.ntp.org appears to be down](https://community.ntppool.org/t/2-uk-pool-ntp-org-appears-to-be-down/3410)
**Author:** [@nottstrekkie](https://community.ntppool.org/u/nottstrekkie)\ **Replies:** 12\ **Last updated:** [June 24, 2024, 12:46pm UTC](https://community.ntppool.org/t/2-uk-pool-ntp-org-appears-to-be-down/3410 "2024-06-24T12:46:14Z")
Hello I tried to send a courtesy email to ask AT ntp DOT org let someone know that 2.uk.pool.ntp.org is not responding to pings. The other servers with prefixes of 0, 1 and 3 appear to be responding to pings normally. … --- ## [UT1 ("true GMT") as an alternative to leap smearing?](https://community.ntppool.org/t/ut1-true-gmt-as-an-alternative-to-leap-smearing/3363)
**Author:** [@Badeand](https://community.ntppool.org/u/Badeand)\ **Replies:** 5\ **Last updated:** [May 6, 2024, 2:01am UTC](https://community.ntppool.org/t/ut1-true-gmt-as-an-alternative-to-leap-smearing/3363 "2024-05-06T02:01:55Z")
So, just an idea that popped into my head. Not necessarily something I wanna advocate for, especially not in the pool, but though it might be interesting to hear your thoughts on it. IERS publishes and continuously upda… --- ## [Synchronization issue after a server redate](https://community.ntppool.org/t/synchronization-issue-after-a-server-redate/3342)
**Author:** [@tminz](https://community.ntppool.org/u/tminz)\ **Replies:** 2\ **Last updated:** [April 10, 2024, 5:05pm UTC](https://community.ntppool.org/t/synchronization-issue-after-a-server-redate/3342 "2024-04-10T17:05:23Z")
Hello everyone, I have been trying for several days to set up an NTP daemon that is capable of: Perform the 1st synchronization with the server, regardless of the time difference between the server and the client. Rem… --- ## [Anecdotal erroneous use of NTP](https://community.ntppool.org/t/anecdotal-erroneous-use-of-ntp/3230)
**Author:** [@ebahapo](https://community.ntppool.org/u/ebahapo)\ **Replies:** 0\ **Last updated:** [February 9, 2024, 3:51pm UTC](https://community.ntppool.org/t/anecdotal-erroneous-use-of-ntp/3230 "2024-02-09T15:51:42Z")
Curious tale of broken VPNs, the Year 2038, and certs that expired 100 years ago Had an NTP client been used to discipline the clock from different redundant sources, instead of resetting the time periodically from a si… --- ## [Drop the vendor zone requirement](https://community.ntppool.org/t/drop-the-vendor-zone-requirement/3184)
**Author:** [@Mr.Tao](https://community.ntppool.org/u/Mr.Tao)\ **Replies:** 15\ **Last updated:** [January 17, 2024, 1:34pm UTC](https://community.ntppool.org/t/drop-the-vendor-zone-requirement/3184 "2024-01-17T13:34:03Z")
Obtaining a vendor zone at pool.ntp.org is a task which has been collecting dust for ages. And not just on my desk – several predecessors at the company attempted it and failed. In goodwill, we went far and beyond to adh… --- ## [Central Mexico timezone](https://community.ntppool.org/t/central-mexico-timezone/3110)
**Author:** [@epartida](https://community.ntppool.org/u/epartida)\ **Replies:** 2\ **Last updated:** [November 1, 2023, 7:20pm UTC](https://community.ntppool.org/t/central-mexico-timezone/3110 "2023-11-01T19:20:31Z")
Hello, I would like to know if there will be any change about Mexico not changed their central time anymore. This since 2023 because of the presidential decree. Many servers in Mexico depends these changes not affect th… --- ## [Should the How to Use pools page be updated with an option that uses 'pool' instead of 'server'?](https://community.ntppool.org/t/should-the-how-to-use-pools-page-be-updated-with-an-option-that-uses-pool-instead-of-server/2518)
**Author:** [@chrismartinau](https://community.ntppool.org/u/chrismartinau)\ **Replies:** 4\ **Last updated:** [August 16, 2023, 7:30am UTC](https://community.ntppool.org/t/should-the-how-to-use-pools-page-be-updated-with-an-option-that-uses-pool-instead-of-server/2518 "2023-08-16T07:30:00Z")
Hi there. Please excuse me if I am covering an old discussion, but it occurs to me that given the wide distribution of ntpd 4.2.8 and common support for the ‘pool’ source type that there should at least be an alternative… --- ## [Testing needed for ntpd pool change to whittle outliers](https://community.ntppool.org/t/testing-needed-for-ntpd-pool-change-to-whittle-outliers/2874)
**Author:** [@davehart](https://community.ntppool.org/u/davehart)\ **Replies:** 24\ **Last updated:** [June 21, 2023, 12:26pm UTC](https://community.ntppool.org/t/testing-needed-for-ntpd-pool-change-to-whittle-outliers/2874 "2023-06-21T12:26:12Z")
ntpd has had support for over a decade generally described as “automatic server discovery” that was designed to not only select servers automatically, but also refine the selection over time to stick with servers that co… --- ## [IPv6 polling failures on Debian Linux](https://community.ntppool.org/t/ipv6-polling-failures-on-debian-linux/2841)
**Author:** [@willem](https://community.ntppool.org/u/willem)\ **Replies:** 10\ **Last updated:** [April 21, 2023, 1:48pm UTC](https://community.ntppool.org/t/ipv6-polling-failures-on-debian-linux/2841 "2023-04-21T13:48:27Z")
I’m having a strange issue, when I poll from an OSX based machine I have zero failures, when I do the same from a debian linux based server i have polling failures (about 97% success) Any one who hs been seeing the same… --- ## [Illogical/potentially abusive Amcrest camera default NTP configuration](https://community.ntppool.org/t/illogical-potentially-abusive-amcrest-camera-default-ntp-configuration/2722)
**Author:** [@GaryOkie](https://community.ntppool.org/u/GaryOkie)\ **Replies:** 0\ **Last updated:** [February 17, 2023, 5:38pm UTC](https://community.ntppool.org/t/illogical-potentially-abusive-amcrest-camera-default-ntp-configuration/2722 "2023-02-17T17:38:27Z")
I discovered 3 years ago with the first Amcrest SmartHome AD110 doorbell that it’s NTP configuration has a default single IP of 200.160.0.8 with an update of every 5 minutes. Their newer AD410 doorbell has the exact sam… --- ## [Setting up Chrony and NMEA for time clock](https://community.ntppool.org/t/setting-up-chrony-and-nmea-for-time-clock/2661)
**Author:** [@FranceBB](https://community.ntppool.org/u/FranceBB)\ **Replies:** 21\ **Last updated:** [January 16, 2023, 5:16pm UTC](https://community.ntppool.org/t/setting-up-chrony-and-nmea-for-time-clock/2661 "2023-01-16T17:16:28Z")
Hi there, I’m setting up my first weather station due to a university project and since it won’t always have reliable internet available (it’s gonna be at the top of a mountain in Italy with 2G at best) I’m gonna use a … --- ## [New Quantum Time Server/Client Development NTP-Q](https://community.ntppool.org/t/new-quantum-time-server-client-development-ntp-q/2527)
**Author:** [@matthewshawnlindholm](https://community.ntppool.org/u/matthewshawnlindholm)\ **Replies:** 0\ **Last updated:** [August 31, 2022, 1:42am UTC](https://community.ntppool.org/t/new-quantum-time-server-client-development-ntp-q/2527 "2022-08-31T01:42:59Z")
Hey, Does anyone want to help build a better time network or want help building a better time network? I’ve been working on some mathematics and think a new standard NTP-Q or NTP-Quantum is a good idea. Has anyone at… --- ## [FYI: removing server from the pool](https://community.ntppool.org/t/fyi-removing-server-from-the-pool/2424)
**Author:** [@marco.davids](https://community.ntppool.org/u/marco.davids)\ **Replies:** 7\ **Last updated:** [June 6, 2022, 2:26pm UTC](https://community.ntppool.org/t/fyi-removing-server-from-the-pool/2424 "2022-06-06T14:26:14Z")
As an experiment I removed a couple of my servers from the pool. And as expected; even after a couple of weeks, quite a few queries are still coming in: That is why I wonder if it wouldn’t be better to recommend the p… --- ## [Device configuration to use IPs within China](https://community.ntppool.org/t/device-configuration-to-use-ips-within-china/2387)
**Author:** [@pgt](https://community.ntppool.org/u/pgt)\ **Replies:** 2\ **Last updated:** [May 6, 2022, 12:18pm UTC](https://community.ntppool.org/t/device-configuration-to-use-ips-within-china/2387 "2022-05-06T12:18:33Z")
Hello. I’m attempting to configure some devices that need to be configured for all IP traffic to remain within China. I was able to configure them to use {0,1,2,3}.cn.pool.ntp.org, but at times a few of these are resulti… --- ## [Ntpd client not sync time when server is reachable](https://community.ntppool.org/t/ntpd-client-not-sync-time-when-server-is-reachable/2363)
**Author:** [@wujinge](https://community.ntppool.org/u/wujinge)\ **Replies:** 2\ **Last updated:** [April 30, 2022, 6:12pm UTC](https://community.ntppool.org/t/ntpd-client-not-sync-time-when-server-is-reachable/2363 "2022-04-30T18:12:35Z")
Version ntpd 4.2.8p15@1.3728-o Tue Apr 26 08:01:21 UTC 2022 (3) /usr/sbin/ntpd -d -g -p /var/run/ntpd.pid -n -c /etc/ntpd.conf 5 Apr 10:55:47 ntpd\[3167\]: ntpd 4.2.8p15@1.3728-o Tue Apr 26 08:01:21 UTC 2022 (3): Startin… --- ## [Ntpd not set time immediately](https://community.ntppool.org/t/ntpd-not-set-time-immediately/2358)
**Author:** [@wujinge](https://community.ntppool.org/u/wujinge)\ **Replies:** 7\ **Last updated:** [April 30, 2022, 1:56pm UTC](https://community.ntppool.org/t/ntpd-not-set-time-immediately/2358 "2022-04-30T13:56:42Z")
ntp client(192.168.40.232) → ntp server (192.168.41.15 with local clock) Server ntpd - NTP daemon program - Ver. 4.2.8p9 run ntpd with /etc/ntp.conf (only local clock) restrict default server 127.127.1.0 burst pre… --- ## [Request Fix Amman Time Zone](https://community.ntppool.org/t/request-fix-amman-time-zone/2313)
**Author:** [@Janti](https://community.ntppool.org/u/Janti)\ **Replies:** 6\ **Last updated:** [April 29, 2022, 9:19am UTC](https://community.ntppool.org/t/request-fix-amman-time-zone/2313 "2022-04-29T09:19:36Z")
Dear Team, i’m new on this, kindly help fix Time Zone of Amman, Jordan, as it’s changed , and sync with pool.ntp.org provide time without change to summer time, summer time switch commenced this year on last Friday of… --- ## [NTP Backup Servers](https://community.ntppool.org/t/ntp-backup-servers/2353)
**Author:** [@Georg](https://community.ntppool.org/u/Georg)\ **Replies:** 4\ **Last updated:** [April 25, 2022, 5:26pm UTC](https://community.ntppool.org/t/ntp-backup-servers/2353 "2022-04-25T17:26:35Z")
I don't know if I get the Concept of this Selection right. 0.de.pool.ntp.org 1.de.pool.ntp.org 2.de.pool.ntp.org 3.de.pool.ntp.org Wouldn't it be better to have different Providers like this? 0.de.pool.ntp.org 0.ch.pool… [Next page](https://community.ntppool.org/c/clients/10.md?page=1)