The chrony pool directive requests a list of servers via DNS and uses (by default) up to four of them for time synchronization. Chrony will also also put new servers into its list if some of the existing ones become unavailable.
This means that configuring four pools will result in chrony talking to sixteen time servers, which is not reasonable.
What we want instead is one pool of four servers.
Why hard-code the 2.… entry from our vendor pool?
The NTP pool only returns IPv4 addresses for the 0., 1. and 3. entries, which would break IPv6-only deployments.
This is also what some distributions do. See this link for a discussion.
The chrony
pooldirective requests a list of servers via DNS and uses (by default) up to four of them for time synchronization. Chrony will also also put new servers into its list if some of the existing ones become unavailable. This means that configuring four pools will result in chrony talking to sixteen time servers, which is not reasonable.What we want instead is one pool of four servers.
Why hard-code the
2.… entry from our vendor pool? The NTP pool only returns IPv4 addresses for the0.,1.and3.entries, which would break IPv6-only deployments. This is also what some distributions do. See this link for a discussion.