Using NTP peer option

Hi all

In Lab 6, section 6.2 "ntp peers" is being used.  In the solution, it said that both the routers should have each other has peers.

If one router is at 6 AM and other is at 9 AM, how will it sychronize.

 

In the Cisco site, I read that with if we use ntp peers instead of ntp server, the server will synchronize with the client. I am not getting what this means?

 

Can someone explain the use of ntp peer and it's working.

 

 

 

Wiht regards

Kings

Comments

  • Peers are the only class that allow for both responses to NTP Requests as well as acceptance of NTP Updates, whereas an NTP Server will only respond to Requests while not permitting updates.  More details provided in the link below.  Synchronization will occur as either a gradual phase or step phase as detailed in RFC 1305.

    There is additional info available on INE's Blog here - http://blog.internetworkexpert.com/tag/ntp/ - that may clear up some missing points for you.

    HTH,

    Brett

  • NTP peers are used for flat NTP architecture. With peers, it can synchronize and get synchronized with the peer. But it will take time for each other to get into same time.

     

    My understanding is that as each other sends and recieves time info to and from each other, at one point of time they will become synchronized. Do we need ntp master to be configured, for ntp peer. Which of the following is valid configuration?

    I tried on my routers, both of these configuration doesn't seem to work.

     

    R1

    ntp master
    ntp peer 10.20.30.41

    R2

    ntp master
    ntp peer 10.20.30.42

     

    or

     

     

    R1

    ntp peer 10.20.30.41

     

    R2

    ntp peer 10.20.30.42

     

     

    With regards

    Kings

  • One 'ntp master' should suffice as I believe we will only learn time from another already synchronized device. Is either device synchronized? Have you run any ntp debugs? Have you set the clocks on both routers?  Any ACLs in use?

  • It seems, NTP peers will used for backups where when the master reference clocks would fail then they would still synchronize with the peers.

    The peers should be fully meshed. Even if the master fail, they get the time updates from the peer.

    But I am not getting the exact picture when and where we would use the NTP peers. The problem is, it takes lot of time, sometimes the routers doesn't

    sync using NTP. Because of this I am not able to analyze the bahaviour of routers with NTP peers.

     

    With regards

    Kings

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