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Can anyone help me figure out why my clock isn't syncing?

I can update my clock manually with

$ sudo sntp -s golem.canonical.com
17 Aug 08:26:22 sntp[518]: Started sntp
2015-08-17 08:26:22.267847 (+0500) +0.000120

The ntp daemon is running:

$ sudo service ntp status
 * NTP server is running

UDP port 123 is open:

$ sudo  nmap -sT -sU -p 123 localhost

Starting Nmap 6.40 ( http://nmap.org ) at 2015-08-17 08:30 EDT
Nmap scan report for localhost (127.0.0.1)
Host is up (0.00013s latency).
PORT    STATE  SERVICE
123/tcp closed ntp
123/udp open   ntp

Nmap done: 1 IP address (1 host up) scanned in 1.07 seconds

Also, ntpq -p comes back with a whole lotta nothing:

$ ntpq -p
     remote           refid      st t when poll reach   delay   offset  jitter
==============================================================================
 www.amsatfox.or .INIT.          16 u    -  128    0    0.000    0.000   0.000
 96.44.142.5     .INIT.          16 u    -  128    0    0.000    0.000   0.000
 origin.towfowi. .INIT.          16 u    -  128    0    0.000    0.000   0.000
 tock.eoni.com   .INIT.          16 u    -  128    0    0.000    0.000   0.000
 golem.canonical .INIT.          16 u    -  128    0    0.000    0.000   0.000

However, my clock always falls behind the official time at a rate of about 500 milliseconds per day.

1

If the refid is .INIT., your ntp daemon has not been able to reach the servers. NTP has no time source to provide time from. It appears port 123 is being blocked somewhere.

  • Ensure UDP port 123 is open outgoing on the your firewall.
  • It is also possible your ISP or their provider is blocking NTP access. This started happening after recent use of NTP in generating DDOS attacks. I still had service on an IPv6 tunnel while IPv4 access was being blocked.
  • Ensure UDP port 123 is open outgoing on the your firewall. : I am on a university campus. Can you tell me how to check this with UDP123? – user1717828 Aug 17 '15 at 13:22
  • Ah hah! I checked with ITS and it turns out my university blocks foreign NTP server connections. They gave me the local addresses to use. Thanks! – user1717828 Aug 17 '15 at 14:22

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