shell-things/etc/chrony
2022-12-06 14:47:45 +02:00
..
conf.d chrony/conf.d: add require-nts.conf 2022-12-06 14:47:45 +02:00
sources.d etc/chrony/sources.d/dna-moi: turn to pool of 3 2022-12-05 13:21:52 +02:00
chrony.conf chrony: cut chrony.d/ into conf.d/ and sources.d/ 2021-01-29 12:56:38 +02:00
README.md etc/chrony/README.md: note GH cadusilva's check command 2022-11-26 12:30:24 +02:00

Chrony config files

For some reason Debian package for Chrony doesnt include other config files so that has to be done by hand like

confdir /etc/chrony/chrony.d

Windows

Refer to ../../Windows/time/README.md

Other random notes

On pools, the default maxsources is 4 and pools would be resolved until there would be 4 names while the documentation for Telia and Snopyta says they have only 3. Cloudflare again resolves to two per IP version, so I assume that means 2.

Commands of interest:

Chrony itself

Note: -N uses names specified in config instead of reverse name lookupping then.

  • chrony -N activity - what sources are doing
  • chrony -N authdata - can show that server uses NTS
  • chrony -N ntpdata - a lot of data on the servers
  • chronyc offline - offline mode
  • chronyc online - reconnects servers
  • chrony -N sources - used timeservers and their statuses
  • chrony -N tracking - local status (stratum and own clock etc.)

nmap

Checking that something is an NTP server? Needs root:

nmap -sU -p 123 --script=ntp-info 192.168.0.1

Checking that something has NTS?

nmap -p 4460 -Pn ntp.example.net

In GitHub user jauderhos curated NTS list user cadusilva suggests this command instead:

chronyd -Q -t 3 'server NTP_SERVER_HERE iburst nts maxsamples 1'

Firewall configuration

In case local clients or peers are wanted,

ufw allow from 192.168.0.0/16 to any port 123 proto udp
ufw allow from fe80::/10 to any port 123 proto udp

A bit wide 192.168.x.x, but so is conf.d/local-servers,conf and fe80://10 isnt ULA either.