[ntp:questions] ntpd not responding to sntp from industrial controller

Danny Thomas d.thomas at its.uq.edu.au
Mon Jul 18 20:27:09 UTC 2011


We've got a RedLion industrial controller which uses SNTP but
doesn't seem to receive a response from either an AD domain
controller or from ntpd 4.2.7p136 on linux.

tcpdump shows the packets arriving but no response is sent.

I'm not sure of the best way to debug this so tried
 root at kolanut# /opt/ntp/bin/ntpd -g -D 100 2>&1 | grep 10.24.33.98
 read_network_packet: fd=23 length 52 from 10.24.33.98
 receive: at 1 130.102.2.123<-10.24.33.98 flags 19 restrict 190
 receive: at 1 130.102.2.123<-10.24.33.98 mode 3 keyid 00000000 len 52 auth 3

Nearly all the fields are ignored, so what's causing ntpd
not to respond ?  Key ID ?, stratum of 0 as KOD but v3 client ?


REQUEST FROM RED-LION as displayed in wireshark
====================================================
Network Time Protocol
 Flags: 0x1b
   00.. .... = Leap Indicator: no warning (0)
   ..01 1... = Version number: NTP Version 3 (3)
   .... .011 = Mode: client (3)
 Peer Clock Stratum: unspecified or unavailable (0)
 Peer Polling Interval: invalid (0)
 Peer Clock Precision: 1.000000 sec
 Root Delay:    0.0000 sec
 Root Dispersion:    0.0000 sec
 Reference Clock ID: NULL
 Reference Clock Update Time: NULL
 Originate Time Stamp: NULL
 Receive Time Stamp: NULL
 Transmit Time Stamp: Jul 18, 2011 07:56:18.504990 UTC
 Key ID: 00000000


REQUEST FROM LINUX SNTP UTILITY
====================================================
Network Time Protocol
 Flags: 0x1b
 00.. .... = Leap Indicator: no warning (0)
 ..01 1... = Version number: NTP Version 3 (3)
 .... .011 = Mode: client (3)
 Peer Clock Stratum: secondary reference (15)
 Peer Polling Interval: 8 (256 sec)
 Peer Clock Precision: 1.000000 sec
 Root Delay:    0.0000 sec
 Root Dispersion:    0.0000 sec
 Reference Clock ID: 0.0.0.0
 Reference Clock Update Time: NULL
 Originate Time Stamp: NULL
 Receive Time Stamp: NULL
 Transmit Time Stamp: Jul 18, 2011 09:17:32.544954 UTC


pidfile     /var/run/ntpd.pid
driftfile   /var/lib/ntp/drift

peer  ntp0.uq.edu.au  iburst  prefer
peer  ntp1.uq.edu.au  iburst
peer  ntp3.uq.edu.au  iburst

server  time-B.timefreq.bldrdoc.gov  iburst
server                time.nist.gov  iburst
server          ntp.adelaide.edu.au  iburst
server             ntp0.cs.mu.oz.au  iburst
server       ntp.thistledown.com.au  iburst  # in au.pool.ntp.org

server  2001:6b0:17:f0a0::11             iburst  # timehost.lysator.liu.se GPS
server  2610:8:7800:0:211:85ff:fe5c:c399 iburst  # otc1.psu.edu WWV (was ntp3)
server  2001:470:0:50::2                 iburst  # clock.fmt.he.net CDMA
server  2001:1488:cde0::1                iburst  # ntp.nic.cz GPS
server  2001:12ff:0:7::186               iburst  # a.st1.ntp.br IRIG
server  2001:67c:21c::3                  iburst  # ntp.amnic.net GPS
server  2001:628:2030:dcf1::ac0          iburst  # ts1.aco.net DCF77  (Austria)
server  2001:44b8:1::1                   iburst  # ntp.on.net [internode]
server  2001:470:1f0f:b4:123::1          iburst  # ipv6.tick.mattnordhoff.com

restrict  default  nomodify notrap nopeer




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