2006-05-01
FreeBSD ntpd PPS setup (PPS slave)
I set up a new ntp server at work, and it is coupled to the meinberg gps timestandard. The meinberg is a very reliable time source but I don't want to invite the entire Internet to come over and bash it.So an 'old' (2001) Dell PowerEdge 2550 got repurposed as FreeBSD ntp server. A lot nicer than it's previous role: windows domain controller.
The kernel:
FreeBSD metronoom 5.4-RELEASE-p13 FreeBSD 5.4-RELEASE-p13 #2: Fri Apr 21 16:09:21 UTC 2006 root@metronoom:/usr/obj/usr/src/sys/METRONOOM i386
The special bit in the kernel config is
options PPS_SYNC # for ntpdin devfs.conf I link cuaa0 (first serial port) to pps0, so ntpd can open /dev/pps0 which is for clockdriver 22:link cuaa0 pps0And ntp.conf:# get time from stardate server stardate.cs.uu.nl prefer iburst driftfile /var/ntp/ntp.drift # fudge a local clock at stratum 10 server 127.127.1.0 fudge 127.127.1.0 stratum 10 # talk pps enable pps kernel auth server 127.127.22.0 # minpoll 4 maxpoll 4 version 4 fudge 127.127.22.0 flag3 1 fudge 127.127.22.0 refid PPS # access restrictions . localhost and staff can check everything. rest can # get the time restrict 127.0.0.1 restrict 131.211.80.0 mask 255.255.254.0 restrict default kod notrap nopeer noquery keys /etc/ntp.keys trustedkey 3 # moeltiepaas! broadcast 224.0.1.1 ttl 2 key 3 # announce policy setvar access_policy="experimental server not suitable for production" default