On Wed, 11 Feb 2015, at 12:32 AM, Reyk Floeter wrote: > Let me share the answer to a question that I got in a private mail: > > > On Tue, Feb 10, 2015 at 10:55:53AM +0100, Reyk Floeter wrote: > >> ---snip--- > >> servers pool.ntp.org > >> constraints from "https://www.google.com/search?q=openntpd"; > >> constraints from www.twitter.com > >> constraint from www.apple.com > >> ---snap--- > >> > > > > Is the last "constraint" in singular pointing to www.apple.com valid or is > > it a typo? > > > > Yes, it is valid. As mentioned in the man page, it works like the > existing server vs. servers for NTP peers. > > When a hostname or URL is specified, ntpd(8) will resolve the host. > The singular version will use only one of the returned IP addresses > and the plural version will use it as a pool and use all of the > returned IP addresses. > > Following the example, a "dig A" on www.google.com or www.apple.com > will typically show you a number of addresses, while the Akamai-hosted > www.apple.com only returns one address near you. You're free to use > any host, and some people might prefer to use their own trusted > servers, I just picked some examples with good availability and > seemingly good time. > > Reyk >
Using `constraints` I see it trying to query both the IPv4 addresses and the IPv6 addresses that the hostname resolves to, even though the machine has no IPv6 access. Is this expected? -- Carlin
