Junos OS

 View Only
last person joined: 18 hours ago 

Ask questions and share experiences about Junos OS.
  • 1.  VMTP in NTP association refid

    Posted 30 days ago

    We had been syncing time on our EX switches to a Windows Active Directoy domain controller.  The IT folks installed new DCs and scuttled the old ones that we had been using.  After switching the NTP server settings to the new IPs, the EXs will no longer sync.  When I do a show ntp association, I see .VMTP. under the refid for the servers.  Doing a packet sniff on the firewall between them, I see communication back and forth.

    jmickens@Clinton-4300-Core> show ntp associations 
       remote         refid           auth st t when poll reach   delay   offset  jitter
    ====================================================================================
     10.18.196.11     .VMTP.             -  1 -  275  512    0    0.000    0.000 4000.00
     10.18.196.12     .VMTP.             -  1 -  271  512    0    0.000    0.000 4000.00

    Does anyone know what VMTP means?  I can't find anything on it, but certainly seems like the switch doesn't like it.

    jmickens@Clinton-4300-Core> show ntp status  
    status=c011 sync_alarm, sync_unspec, 1 event, event_restart,
    version="ntpd 4.2.0-a Sat Feb 24 02:16:07  2024 (1)",
    processor="powerpc", system="JUNOS21.4R3-S6.5", leap=11, stratum=16,
    precision=-19, rootdelay=0.000, rootdispersion=8.655, peer=0,
    refid=INIT, reftime=00000000.00000000  Thu, Feb  7 2036  1:28:16.000,
    poll=4, clock=ead3a241.c8ecc724  Mon, Nov  4 2024 14:42:57.784, state=1,
    offset=0.000, frequency=-79.385, jitter=0.002, stability=0.000

    jmickens@Clinton-4300-Core> set date ntp 
     4 Nov 14:43:32 ntpdate[55674]: no server suitable for synchronization found



    ------------------------------
    JIM MICKENS
    ------------------------------


  • 2.  RE: VMTP in NTP association refid

    Posted 30 days ago

    Looks like a Microsoft Windows NTP server ?

    https://www.researchgate.net/profile/Michael-Lombardi-4/publication/331219265_Rethinking_Timekeeping_for_Modern_IT_Solutions/links/5c828a80299bf1268d483bfa/Rethinking-Timekeeping-for-Modern-IT-Solutions.pdf

    Inside a Windows VM, the VM Time Provider (VMTP) is an active component of W32Time. The Windows VM acts as an NTP client by relying on the VMTP to synchronize its system clock with that of the Hyper-V host. The Hyper-V host acts as an NTP server at a "higher" stratum. In NTP principles, a Sync-n-Scale enabled Hyper-V host occupies stratum 1, and its VMs are all at stratum 2.

    Therefore VMTP is just the name of the time source used by your NTP Servers.

    And, indeed, it's not properly synced with a proper time source, so their NTP stratum should be bad. You should use some kind of ntpdate to debug what it answers...



    ------------------------------
    Olivier Benghozi
    ------------------------------



  • 3.  RE: VMTP in NTP association refid

    Posted 29 days ago

    It's definitely a Windows VM .  I've never seen the .VMTP. refid before - not even when we were pointed at the old domain controllers.  The IT staff is going to look at the servers for any anomalies with regards to NTP.  I've forwarded that information to them.



    ------------------------------
    JIM MICKENS
    ------------------------------