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Using Bundles to Create Logical Configurations for Physical Interfaces, CTP Release 7.3, CTPView Release 7.3
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primary node configured. You can configure up to four master modes, each of which can
send their clocking information to a maximum of 10 slaves and the slave node can receive
clocking information from the configured master nodes.
You can configure the four master nodes using CTP Menu or the CTPView web server
during Netref slave configuration. As a result, a single slave node can use the IP address
of up to four master nodes while you configure Netref slave node settings.
Each master node is assigned a priority during Netref slave configuration. The master
node with the highest priority is assigned Priority 1, the second highest priority for the
master node is Priority 2, and so on. You cannot configure the priority of the master nodes.
The priorities assigned are unique for each masters while configuring Netref slave nodes.
The slave nodes synchronize their local clock with the clock of the highest priority master
node (Priority 1 master node). After the highest priority master goes down or when a
problem occurs during the clock synchronization phase, the CTP device switches to its
next highest priority master (Priority 2 master node). The slave nodes synchronize their
clock with the clock of Priority 2 master node. The priorities of the master nodes are also
switched in the backend, after switching of the master nodes takes place. In the case of
flapping between the masters, the primary master (high priority) is retained or binding
with the master that contains a good clock quality is maintained.
When switching of the masters takes place, an event of mastership change is logged
into the syslog messages. The slave node synchronization query provides the details of
the master node to which the slave is locked and the details of the configured master
nodes along with their assigned priorities. You cannot configure the lowest priority masters
until its higher priority masters are configured. Similarly, you cannot disable the highest
priority masters until its lower priority masters are disabled.
When a node is configured as NetRef Master, it starts generating the NetRef packets and
send them to the slave nodes. The slave node accepts the packets from the highest
priority master node and the NetRef state of the slave node is changed to wait state. If
16 sequenced packets are received by the slave nodes, the NetRef state is changed from
Wait state to Aggressive state. At this stage, if 8 packets are missed continuously, the
NetRef state again moves back to the Wait state. These NetRef packets are processed
and slope is calculated. Based on the slope, the clock of the slave node is in
synchronization with the master node and the state changes to the Maintain state. The
state changes from Maintain or Aggressive to Starvation when no NetRef packet is
received in last 20 seconds. As soon as the node goes to Starvation state, switching of
the master takes place. The packets are processed by the slave nodes to synchronize
their clock with the next highest priority master node. Flapping of the masters occurs if
you continuously "round robin" to each master and wait for 20 seconds for an incoming
NetRef packet.
Copyright © 2018, Juniper Networks, Inc.
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