[ntp:questions] "The NTP network is a forest of hosts(...)"

Ulrich Windl Ulrich.Windl at RZ.Uni-Regensburg.DE
Wed Jun 28 10:09:09 UTC 2006


Hi,

a "forest" being a "set of trees", I have a question with the statement cited:
I doubt that NTP sync graph is tree-like (each node having eactly one parent,
and the graph having no cycles). Especially with "peer" synchronization with
peers being at the same startum.

The statement was taken from page 7 of "NTP Security Model", dealing with the
basics of autokey. Assuming a tree graph makes the understanding more simple,
but reality makes implementation quite fuzzy: Which nodes on a group do need
"CA certificates" (trusted), especially if the topmost level of the group are
multiple peers at the same stratum.

As I understood it, NTP propagates trust "down the stratum" (low numbers to
higher numbers). When initially staring the servers, it's unsure which one
will sync first, and thus have the lowest startum (and therefore the need for
the trusted certificate).

Did I mis-interpret anything?

At the moment one statum-2 peer has a flash of 408 (no_access, not_proventic,
...) while the other peer (with a disconnected refclock) has flash of 608
(no_access, bad_autokey, not_proventic)

Regards,
Ulrich




More information about the questions mailing list