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+# aus-ntps
+
+A collection of Australian NTP servers
+
+Each table contains the following information:
+
+- **Endpoint**: the hostname (or IP address) and port number of the NTP server being queried
+- **IP Address**: the IP address of the host
+- **Version**: the NTP version of the NTP server
+- **Stratum**: the reported [stratum value](https://en.wikipedia.org/wiki/Network_Time_Protocol#Clock_strata) of the NTP server
+- **Leap**: the reported leap indictor of the NTP server
+
+An endpoint may have zero or more IP address, version, stratum, and leap combinations. An endpoint with no entries indicates that a DNS record exists for the host, but that no NTP server exists or it was otherwise inaccessible by the Python script. For example, Aussie Broadband's NTP servers [only respond to customers](https://www.aussiebroadband.com.au/help-centre/internet/ntp-settings/). You may find it useful to test these endpoints yourself for this reason, particularly if the subdomain name of the endpoint begins with `ntp`, `time`, or one of the other [predefined names](src/NtpDnsProbeDiscoveryService.py#L14-L40). Further details about the information above can be obtained [here](https://docs.ntpsec.org/latest/ntpdig.html).
+
+You should use the endpoint when configuring an NTP client or server. For example:
+
+```conf
+# /etc/ntpsec/ntp.conf
+...
+server tic.ntp.telstra.net iburst
+```
+
+## Useful Resources
+
+- If you are looking for the Australian Government's NTP servers, please be aware they are only available to [registered users](https://www.industry.gov.au/national-measurement-institute/physical-measurement-services/time-and-frequency-services).
+
+- Some ISPs may drop NTP traffic if the [outbound source port is port 123](https://docstore.mik.ua/orelly/networking_2ndEd/fire/ch22_05.htm) (well known NTP port number) and restrict access to some predefined ISP-controlled NTP servers. You may be able to bypass this restriction by altering the source port. One method is to add the [following iptables rule](https://superuser.com/a/1380558) to your router.
+
+```shell
+iptables -t nat -I POSTROUTING -p udp -m udp --sport 123 -j MASQUERADE --to-ports 49152-65535
+```
+
+## Servers
+
+### Spectrum Networks
+
+| endpoint | ip address | version | stratum | leap |
+| -------- | ---------- | ------- | ------- | ---- |
+|`ns1.spectrum.com.au:123`|||||
+|`ns2.spectrum.com.au:123`|||||
+||203.14.108.10|4|s11|no-leap|
+|`ns3.spectrum.com.au:123`|||||
+|`ns4.spectrum.com.au:123`|||||
+|`ntp.spectrum.com.au:123`|||||
+||202.68.160.8|4|s3|no-leap|
+|`spectrum.com.au:123`|||||
+|`time.spectrum.com.au:123`|||||
+||202.68.160.8|4|s3|no-leap|
+
+Data last updated 2024-08-02 15:32:25.021783+00:00