I have a few Jetson-TK1 boards that do not have a real-time clock and consequently loses their time whenever it is powered off. I would like to set each one so when they power on, their clock gets set. The kicker is I may or may not be connected to the internet so I want my laptop (which also may or may not be on the internet) setup as an ntp server, so the Jetsons can get their time from it.

I am trying to follow this, this, and this post. I can get the TK1 to update on startup, albeit somewhat slowly. I cannot get it to get the time from my laptop (both are running Ubuntu). In the first post it says to "specify your own server address" when setting up the server. What should that address be? The address of the server I'm trying to setup (i.e. the machine's own IP address)? It seems like there should be more to setting up the server than what is given in that post. What am I missing?

1 Answer 1


That configuration is for general use, you have gateway or machine that get time from Internet. It is ok, if you are having an isolated network. So:

  • Server ntp: Don't care about server IP. (You laptop in this case)

    Verify the you have ntp UDP port open:

    ~$ sudo netstat -ulp | grep :ntp
    udp        0      0           *:*                                 3437/ntpd       
    udp        0      0 localhost:ntp           *:*                                 3437/ntpd       
    udp        0      0 *:ntp                   *:*                                 3437/ntpd       
    udp6       0      0 fe80::b265:8d33:8fd:ntp [::]:*                              3437/ntpd       
    udp6       0      0 ip6-localhost:ntp       [::]:*                              3437/ntpd       
    udp6       0      0 [::]:ntp                [::]:*                              3437/ntpd

    or using sudo netstat -ulpn | grep :123

    If you have a firewall, allow packets to port 123.

  • Client ntp: Change its ntp server to your laptop IP.

    Default installation sync using ntpdate on network connection up:


    If you setup ntp daemon, then change it here too:


    Verify connection to server:

    ~$ sudo ntpdate
     8 Jul 17:42:30 ntpdate[8968]: adjust time server offset 0.003846 sec

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