[ntp:questions] avoiding large steps (on time island)

Serge Bets serge.bets at NOSPAM.laposte.invalid
Sun Jun 3 12:50:43 UTC 2007


Hello Sean,

 On Monday, May 21, 2007 at 13:07:53 -0700, seanjlangford at gmail.com wrote:

> they are a collection of portable devices which are
> connecting/disconnecting from the network and powering up/down
> arbitrarily.

Then you could abandon the hierarchical model with one 127.127.1.0
master, and try an all-peers orphanage instead. This may seem better
adapted to your case, and may statistically reduce the risk of whole
network steps when new machines are powered up. Reduce, not suppress,
unfortunately: Just started orphans taking the leadership seems to
happen randomly.

Depending on total number of nodes and number of networks, you can
choose any way of peering: "peer" each other, everybody broadcasts,
or everybody multicasts. Manycast doesn't seem to work in an isolated
orphanage, unfortunately. Example ntp.conf for the broadcast scheme:

| logfile /var/log/ntpd.log
| driftfile /var/lib/ntp/drift
| tos orphan 10
| keys /etc/ntp.keys
| trustedkey 1
| broadcastclient
| broadcast 192.168.2.255 key 1


Serge.
-- 
Serge point Bets arobase laposte point net




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