[ntp:questions] peer command and clusters

Florin Andrei florin at andrei.myip.org
Fri Mar 25 19:38:33 UTC 2011


Two groups of machines in two datacenters, VPN line in between. Two NTP 
servers in each datacenter, sync'ing to public servers. Local networks 
are gig ethernet.

Sometimes there seem to be issues with the public servers, so I figured 
I may as well use the "peer" command to at least keep the local servers 
as close to each other as possible, since I've a few clusters where it's 
more important that all members agree on the same time base, even when 
that base might not be very accurate.

So I came up with this configuration for the local NTP servers. Please 
criticize it.

###########################################################
server 0.us.pool.ntp.org
server 1.us.pool.ntp.org
server 2.us.pool.ntp.org
server 3.us.pool.ntp.org

restrict 0.us.pool.ntp.org mask 255.255.255.255 nomodify notrap noquery
restrict 1.us.pool.ntp.org mask 255.255.255.255 nomodify notrap noquery
restrict 2.us.pool.ntp.org mask 255.255.255.255 nomodify notrap noquery
restrict 3.us.pool.ntp.org mask 255.255.255.255 nomodify notrap noquery

# comment out your own name
#
peer ntp1
#peer ntp2
peer ntp3
peer ntp4

driftfile /var/lib/ntp/drift

# allow NTP clients to query this server
#
restrict XXX.YYY.ZZZ.0 mask 255.255.255.0 nomodify notrap

# allow local queries
#
restrict 127.0.0.0 mask 255.0.0.0

# disallow everybody else
#
restrict default ignore
###########################################################

-- 
Florin Andrei
http://florin.myip.org/



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