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quiver's avatar
quiver
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Jan 30, 2020

NTP monitor

I am looking for a external health monitor for NTP servers, so that if one of the NTP server lost sync or ntp status switched to stratum 2, instead of marking it down in F5, I want that pool member priority to be lower than the other working one. Any help will be much appreciated.

2 Replies

  • Hi Jai, please see below the VS and pool config. The current set up is : traffic to two NTP servers load-balanced (source address persistent) by F5 ( IOS 12.1). Problem is, current VS set up monitoring udp 123 port. Its not checking if the ntp server actually lost the sync (stratum greater than 1 o 0). So I want to set up an external monitor, which will monitor whether NTP server on stratum 1, if it loses the stratum 1, then make it forced offline, and when it restored make it enabled again.. In addition to that, if the external monitor could see both NTP Servers lost sync at given time, then switch to default udp_123 monitoring. As we don't want to lose NTP server all together.

     

     

     

     ltm virtual cus-ntp-01 {

      destination 21.12.63.252:ntp

      ip-protocol udp

      mask 255.255.255.255

      persist {

        source_addr {

          default yes

        }

      }

      pool cus-ntp

      profiles {

        udp { }

      }

      source 0.0.0.0/0

      translate-address enabled

      translate-port enabled

      vs-index 26

    }

    ltm pool cus-ntp {

      allow-snat no

      members {

        2.10.91.61.6:ntp {

          address 2.10.61.6

          session monitor-enabled

          state up

        }

        2.10.61.7:ntp {

          address 2.10.61.7

          priority-group 2

          session monitor-enabled

          state up

        }

      }

      min-active-members 1

      monitor min 1 of { udp_123 }

    }