Provide alert if configured NTP server can not be contacted
Since clock skew of even a handful of seconds can break AD, configure the Alert system to check if the ntp server can be contacted.
nc -vzu 10.212.0.2 123
Connection to 10.212.0.2 123 port [udp/ntp] succeeded!
Add NTP alert, in case peer is not reachable, as well as some other
related sanity checks. More thorough ones can be derived.
#1 Updated by Ash Gokhale over 2 years ago
perhaps parse output of ntptime and error when skew is more that 3sec:
ntp_gettime() returns code 0 (OK)
time dc5b2c61.ac711d7c Fri, Feb 24 2017 14:04:17.673, (.673601196),
maximum error 83202885 us, estimated error 2836 us, TAI offset 0
ntp_adjtime() returns code 0 (OK)
modes 0x0 (),
offset 0.000 us, frequency 27.608 ppm, interval 1 s,
maximum error 83202885 us, estimated error 2836 us,
status 0x2001 (PLL,NANO),
#5 Updated by William Grzybowski about 2 years ago
- Project changed from TrueNAS to FreeNAS
- Category changed from 224 to 53
- Priority changed from Important to Expected
- Target version changed from 11.0 to 11.1
Moving to FreeNAS since its no specific to make sure it makes into the next feature set release.
#9 Updated by Timur Bakeyev about 2 years ago
- Status changed from Screened to Investigation
There is an
ntplib Python lib, that performs basic NTP operations.
#!/usr/local/bin/python # import time import ntplib from ntplib import NTPClient, NTPException #NTP_SERVER = "0.freebsd.pool.ntp.org" NTP_SERVER = "10.0.255.250" NTP_SERVER_BAD = "www.microsoft.com" client = NTPClient() info = client.request(NTP_SERVER) # ntpdate -q 10.0.255.250 #server 10.0.255.250, stratum 3, offset 0.001706, delay 0.02589 # 7 Jul 04:19:18 ntpdate: adjust time server 10.0.255.250 offset 0.001706 sec print("server %s, stratum %d, offset %f, delay %f" %(NTP_SERVER, info.stratum, info.offset, info.root_delay)) # check response #self.assertTrue(isinstance(info, ntplib.NTPStats)) print("Version: %d" % info.version) print("Offset: %f" % info.offset) print("Stratum: %x" % info.stratum) print("Precision: %x" % info.precision) print("Root delay: %f" % info.root_delay) print("Root dispersion: %f" % info.root_dispersion) print("Delay: %d" % info.delay) print("Leap: %d" % info.leap) #self.assertIn(info.leap, ntplib.NTP.LEAP_TABLE) print("Poll: %x" % info.poll) print("Mode: %d" % info.mode) #self.assertIn(info.mode, ntplib.NTP.MODE_TABLE) print("Refid: %x" % info.ref_id) print("TX time: %f" % info.tx_time) print("Ref time: %f" % info.ref_time) print("Orig time: %f" % info.orig_time) print("Dest time: %f" % info.dest_time) print("Recv time: %f" % info.recv_time) print("%ld %ld" % ( int(info.tx_time), ntplib.ntp_to_system_time(ntplib.system_to_ntp_time(int(info.tx_time)))) ) print("Leap: %s" % ntplib.leap_to_text(info.leap)) print("Mode: %s" % ntplib.mode_to_text(info.mode)) print("Stratum: %s" % ntplib.stratum_to_text(info.stratum)) print("RefID: %s" % ntplib.ref_id_to_text(info.ref_id, info.stratum)) try: new_info = client.request(NTP_SERVER_BAD, timeout=1) except NTPException as ne: print("FATAL: " + ne.message)
]# ntpdate -q 10.0.255.250 server 10.0.255.250, stratum 3, offset 0.003098, delay 0.02585 10 Jul 01:30:42 ntpdate: adjust time server 10.0.255.250 offset 0.003098 sec
server 10.0.255.250, stratum 3, offset 0.003227, delay 0.005920 Version: 2 Offset: 0.003227 Stratum: 3 Precision: -17 Root delay: 0.005920 Root dispersion: 0.056061 Delay: 0 Leap: 0 Poll: 3 Mode: 4 Refid: d5ef9a0c TX time: 1499643047.698076 Ref time: 1499641950.401897 Orig time: 1499643047.694415 Dest time: 1499643047.695232 Recv time: 1499643047.698025 1499643047 1499643047 Leap: no warning Mode: server Stratum: secondary reference (3) RefID: 22.214.171.124 FATAL: No response received from www.microsoft.com.
The output and information obtained via lib comparable to the results of
The library, seems, doesn't support NTP authentication though, not sure, how critical is that.
Haven't tested it on IPv6 peers either.
#10 Updated by Timur Bakeyev about 2 years ago
Implemented nice, simple, easy to understand wrong check. Have to keep in mind, that by default we use
pool.ntp.org addresses they are not bounded to some particular hosts, but randomly picked up by DNS round-robin. So, for meaningful results we need to parse the output of
#15 Updated by Timur Bakeyev over 1 year ago
- Target version changed from 11.1 to 11.1-U1
I forgot about this one :( The code is somewhat working, but I want to test it in tougher conditions. also, there is a ticket, where user got NTP not working in a interesting way - need to check that new code can detect such an issue.