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--- networking:ntp_pools [2021/03/10 04:08] – bstafford
+++ networking:ntp_pools [2021/09/23 10:23] (current) – removed bstafford
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-====== Public NTP Servers ======
-**REMEMBER** : Do NOT use burst or iburst against public NTP servers unless they are announced they accept it (e.g. don't use it against *.ntp.org servers). More details [[networking:ntp#burst_and_iburst|hre]].
-  * There is a dedicated page to [[networking:ntp|general NTP]].
-  * There is a dedicated page to [[infoblox:ntp|Infoblox NTP]].
-===== pool.ntp.org =====
-It is best to use **pool.ntp.org** as an NTP server. This will find the closest available servers for you.
-For the following list of NTP pools, you can use the following and/or prefix 0. or 1. or 2. or 3. to the FQDN
-  * pool.ntp.org
-  * africa.pool.ntp.org (54)
-  * asia.pool.ntp.org (282)
-  * europe.pool.ntp.org (2784)
-  * north-america.pool.ntp.org (934)
-  * oceania.pool.ntp.org (126)
-  * south-america.pool.ntp.org (58)
-  * <country code>.pool.ntp.org (e.g. uk.pool.ntp.org)
-  * <distribution>.pool.ntp.org (e.g. ubuntu.pool.ntp.org. **NOTE** for these you need to prefix 0. or 1. or 2. or 3. to the FQDN)
-The number of active service in the geographic regions can be found [[https://www.ntppool.org/zone/@|here]].
-The 0, 1, 2 and 3.pool.ntp.org names point to a random set of servers that will change every hour.
-Also
-  * pool.ntp.org
-  * 0.pool.ntp.org
-  * 1.pool.ntp.org
-  * 2.pool.ntp.org
-  * 3.pool.ntp.org
-More specific are:
-  * ntp0.ja.net (Stratum 1)
-  * ntp1.npl.co.uk (Stratum 2)
-  * time.cloudflare.com (Stratum 3)
-  * uk.pool.ntp.org
-  * 0.uk.pool.ntp.org
-  * 1.uk.pool.ntp.org
-  * 2.uk.pool.ntp.org
-  * 3.uk.pool.ntp.org
-  * europe.pool.ntp.org
-  * 0.europe.pool.ntp.org
-  * 1.europe.pool.ntp.org
-  * 2.europe.pool.ntp.org
-  * 3.europe.pool.ntp.org
-===== NTP Servers =====
-List of Stratum 1 servers
-  * [[http://tf.nist.gov/tf-cgi/servers.cgi|NIST]]
-  * [[http://support.ntp.org/bin/view/Servers/StratumOneTimeServers|ntp.org]]
-National Physics Laboratory hosts two public "Stratum 2" servers. This means their servers sync directly to atomic clocks.
-**DO NOT** configure your system to use Google Public NTP together with non-leap-smearing NTP servers. e.g. do not combine Google NTP with Cloudflare NTP as they [[https://developers.cloudflare.com/time-services/ntp/usage|do not implement leap smearing]]. Smearing is used by Google, AWS, and Facebook NTP servers but not Cloudflare.
-^Operator ^ Server FQDN ^ Server IP ^ Stratum ^ RefID ^ Source Type or FQDN ^ Delay ^ Location ^ Supports iBurst ^
-| Cloudflare | time.cloudflare.com | 162.159.200.1 | 3 | 10.21.8.19 | Internal Cloudflare? | 13.080 | UK | |
-| Cloudflare | time.cloudflare.com | 162.159.200.123 | 3 | 10.21.8.19 | Internal Cloudflare? | 13.896 | UK | |
-| Microsoft | time.windows.com | 51.145.123.29 | 3 | 25.66.230.5 | Internal Microsoft? | 13.896 | UK | |
-| Zen Internet | ntp0.zen.co.uk | 212.23.8.6 | 2 | 195.66.241.3 | ntp1.linx.net | 11.642 |  | |
-| Zen Internet | ntp1.zen.co.uk | 212.23.10.129 | 2 | 85.199.214.99 | server1.quickdrivingtestcancellations.net | 16.948 | UK | |
-| National Physics Laboratory | ntp1.npl.co.uk | 139.143.5.30 | 2 | 139.143.45.169 | ? | 16.457 | UK | |
-| National Physics Laboratory | ntp2.npl.co.uk | 139.143.5.31 | 2 | 139.143.45.169 | ? | 17.329 | UK | |
-| Manchester University | ntp2a.mcc.ac.uk | 130.88.202.49 | 2 | 193.62.22.66 | ntp0.ja.net | 22.581 | UK | |
-| Manchester University | ntp2b.mcc.ac.uk | 130.88.203.13 | 2 | 130.88.203.13 | ntp0.ja.net | 22.282 | UK | |
-| Manchester University | ntp2c.mcc.ac.uk | 130.88.200.6 | 2 | 193.62.22.66 | ntp0.ja.net | 22.135 | UK | |
-| Manchester University | ntp2d.mcc.ac.uk | 130.88.212.143 | 2 | 193.62.22.74 | ntp1.ja.net | 22.771 | UK | |
-| JANET, Harwell | ntp0.ja.net | 193.62.22.66 | 1 | .MSF. | MSF Radio Clock Receiver | 15.981 | UK | |
-| JANET, Harwell | ntp1.ja.net | 193.62.22.74 | 1 | .MRS. | N/A | 26.042 | UK | |
-| JANET, Harwell | ntp2.ja.net | 193.62.22.98 | 2 | 193.62.22.74 | ntp1.ja.net | 22.849 | UK | |
-| JANET, Harwell | ntp3.ja.net | 193.62.22.90 | 1 | .PPS. | N/A | 26.305 | UK | |
-| JANET, Harwell | ntp4.ja.net | 193.62.22.82 | 1 | .DCFa. | DCF77 | 17.528 | UK | |
-| Google | time.google.com | time1-time4  | 1 |  |  |  | | Yes |
-| Google | time1.google.com | 216.239.35.0  | 1 | .GOOG. | N/A | 20.393 | | Yes |
-| Google | time2.google.com | 216.239.35.4 | 1 | .GOOG. | N/A | 20.399 | | Yes |
-| Google | time3.google.com | 216.239.35.8 | 1 | .GOOG. | N/A | 20.514 | | Yes |
-| Google | time4.google.com | 216.239.35.12 | 1 | .GOOG. | N/A | 22.899 | | Yes |
-| Facebook | time.facebook.com | time1-time5  | 1 |  |  |  | | Yes |
-| Facebook | time1.facebook.com | 129.134.28.123 | 1 | .FB... | N/A | 25.595 | | Yes |
-| Facebook | time2.facebook.com | 129.134.29.123 | 1 | .FB... | N/A | 16.803 | | Yes |
-| Facebook | time3.facebook.com | 129.134.25.123 | 1 | .FB... | N/A | 12.037 | | Yes |
-| Facebook | time4.facebook.com | 129.134.26.123 | 1 | .FB... | N/A | 18.341 | | Yes |
-| Facebook | time5.facebook.com | 129.134.27.123 | 1 | .FB... | N/A | 16.546 | | Yes |
-| Apple | time.apple.com | 17.253.108.253 (and others)  | 1 | .SHM. |  | 17.343 | | Yes |
-| Apple | time.euro.apple.com | 17.253.34.125 (and others) | 1 | .SHM. |  |  9.889 | | Yes |
-| Leo Bodnar Electronics | ntp1.leontp.com | 51.155.16.62 | 1 | .GPS. | N/A | 36.932 | UK | |
-| Leo Bodnar Electronics | ntp5.leontp.com | 85.199.214.98 | 1 | .GPS. | N/A | 16.523 | UK | |
-| Leo Bodnar Electronics | ntp6.leontp.com | 85.199.214.99  | 1 | .GPS. | N/A | 15.949 | UK | |
-| Leo Bodnar Electronics | ntp7.leontp.com | 85.199.214.100 | 1 | .GPS. | N/A | 16.002 | UK | |
-| Leo Bodnar Electronics | ntp8.leontp.com | 85.199.214.101 | 1 | .GPS. | N/A | 16.595 | UK | |
-| Leo Bodnar Electronics | ntp9.leontp.com | 85.199.214.102 | 1 | .GPS. | N/A | 15.965 | UK | |
-| Xentex IT Solutions | ntp.xtx.cloud | 81.133.66.177 | 1 | .PPS. | N/A | 24.301 | UK | |
-More information on Google's NTP offering can be found [[https://developers.google.com/time/faq|here]]. Google 'smear' a leap second over the course of a the hour either side of the leap second. Do not mix NTP servers that 'smear' and NTP servers that do not 'smear'.
-Google uses its own NTP servers (see above) for its public DNS servers (see below). If you cannot configure multiple servers, ''time.google.com'' will automatically select an appropriate Google server nearby.