{"id":295,"date":"2021-03-31T19:25:45","date_gmt":"2021-03-31T17:25:45","guid":{"rendered":"https:\/\/markus-blog.de\/?p=295"},"modified":"2023-04-03T08:43:57","modified_gmt":"2023-04-03T06:43:57","slug":"werde-timekeeper-im-ntp-pool-projekt-mit-deinem-ubuntu-16-04-lts-vps","status":"publish","type":"post","link":"https:\/\/markus-blog.de\/index.php\/2021\/03\/31\/werde-timekeeper-im-ntp-pool-projekt-mit-deinem-ubuntu-16-04-lts-vps\/","title":{"rendered":"Become a timekeeper in the NTP pool project with your Ubuntu 20.04 LTS VPS"},"content":{"rendered":"

If you already have one (or two) VPS, why shouldn’t you become a global timekeeper? If you do not have a VPS you can get one here @netcup<\/a> with 5\u20ac Discount or start at Hetzner Cloud<\/a> with 20\u20ac start credits.<\/p>\n

But now I’ll show you how we configure our VPS to make the time available for other computers around the world.<\/p>\n

Requirements that we should meet:<\/p>\n

– a static public IP address
\n– a permanent and stable internet connection<\/p>\n

If we decide to provide the time in the NTP pool, we should be aware that this is not a short-term decision and that we configure our VPS for this in the longer term.<\/p>\n

Also note the information under http:\/\/www.pool.ntp.org<\/a> and read them carefully.<\/p>\n

If you are sure to join the pool, we will first bring our VPS up to date:<\/p>\n

sudo apt-get -y update && apt-get -y upgrade && apt-get -y dist-upgrade<\/pre>\n
Then we install NTP:<\/p>\n
sudo apt-get install ntp<\/pre>\n
If we have a firewall, we must of course remember to open port 123 UDP incoming. As example with ufw:<\/p>\n
sudo ufw allow 123\/udp<\/pre>\n
We should specify at least four and a maximum of seven time servers in our ntp.conf as a source.<\/p>\n
We look for two Timeservers in the List of Stratum 1 Server<\/a>. It is important that we only use servers that are categorized as „OpenAccess“ under „AccessPolicy“<\/p>\n
\"\"<\/p>\n
Once we have picked out two Stratum 1 time servers, we call the List of Stratum 2 Server<\/a> and look for two of this kind. Again, pay attention to „OpenAccess“.<\/p>\n
Now we have made a note of the servers and adjust the ntp.conf so that we can also get the time from these servers.<\/p>\n
sudo cp \/etc\/ntp.conf \/tmp\/ntp.conf.bak\r\nsudo nano \/etc\/ntp.conf<\/pre>\n
Content should look like this<\/p>\n
# \/etc\/ntp.conf, configuration for ntpd; see ntp.conf(5) for help\r\n\r\ndriftfile \/var\/lib\/ntp\/ntp.drift\r\n\r\n# Enable this if you want statistics to be logged.\r\n#statsdir \/var\/log\/ntpstats\/\r\n\r\nstatistics loopstats peerstats clockstats\r\nfilegen loopstats file loopstats type day enable\r\nfilegen peerstats file peerstats type day enable\r\nfilegen clockstats file clockstats type day enable\r\n\r\n# Specify one or more NTP servers.\r\nserver zeit.domain1.tld      iburst\r\nserver zeit.domain2.tld      iburst\r\nserver zeit.domain3.tld      iburst\r\nserver zeit.domain4.tld      iburst\r\n\r\n# By default, exchange time with everybody, but don't allow configuration.\r\nrestrict -4 default kod notrap nomodify nopeer noquery limited\r\nrestrict -6 default kod notrap nomodify nopeer noquery limited\r\n\r\n# Local users may interrogate the ntp server more closely.\r\nrestrict 127.0.0.1\r\nrestrict ::1\r\n\r\n# Needed for adding pool entries\r\nrestrict source notrap nomodify noquery\r\n<\/pre>\n
everything else can be deleted. If something does not work, we can use the saved configuration with<\/p>\n
sudo cp \/tmp\/ntp.conf.bak \/etc\/ntp.conf<\/pre>\n
Once we have adjusted the configuration, we restart the NTP service:<\/p>\n
sudo systemctl restart ntp.service<\/pre>\n
After a while we will check the status of our time server with the following command:<\/p>\n
ntpq -p<\/pre>\n
The output should look something like this:<\/p>\n
\"\"<\/p>\n
From this step on, we first check from another host whether we can get the time from our time server:<\/p>\n
ntpdate -q hostname.deine-domain.tld<\/pre>\n
Output:
\n\"\"<\/p>\n
If everything works the way we want, then we can register our server with its IP address and make it available to others. To do this, we have to register with  NTP Pool <\/a> and add the server after confirmation:<\/p>\n
\"\"<\/p>\n
Once we have added the server, we just look the next day under Manage Server to see the status of the server. Only servers with a score above 10 are included in the pool; this should generally be the case after approx. 24 hours.<\/p>\n
\"\"<\/p>\n
If there are problems with the server later, we are automatically notified by the pool and can react to them.<\/p>\n
If you have any questions or suggestions for improvement, please let me know … \ud83d\ude42<\/p>\n