3Com 4500 PWR 26-Port Configuration Manual page 592

To implement NTDP, you need to enable NTDP both globally and on specific ports on the
management device, and configure NTDP parameters.
On member/candidate devices, you only need to enable NTDP globally and on specific ports.
Member and candidate devices adopt the NTDP settings of the management device.
Introduction to Cluster
A cluster must have one and only one management device. Note the following when creating a cluster:
You need to designate a management device for the cluster. The management device of a cluster
is the portal of the cluster. That is, any operations from outside the network intended for the
member devices of the cluster, such as accessing, configuring, managing, and monitoring, can
only be implemented through the management device.
The management device of the cluster recognizes and controls all the member devices in the
cluster, no matter where they are located in the network and how they are connected.
The management device collects topology information about all member/candidate devices to
provide useful information for you to establish the cluster.
By collecting NDP/NTDP information, the management device learns network topology, so as to
manage and monitor network devices.
Before performing any cluster-related configuration task, you need to enable the cluster function
first.
On the management device, you need to enable the cluster function and configure cluster parameters.
On the member/candidate devices, however, you only need to enable the cluster function so that they
can be managed by the management device.
Cluster maintenance
1) Adding a candidate device to a cluster
To create a cluster, you need to determine the device to operate as the management device first. The
management device discovers and determines candidate devices through NDP and NTDP, and adds
them to the cluster. You can also add candidate devices to a cluster manually.
After a candidate device is added to a cluster, the management device assigns a member number and
a private IP address (used for cluster management) to it.
2) Communications within a cluster
In a cluster, the management device maintains the connections to the member devices through
handshake packets.
management device and a member device.
Figure 48-3 illustrates the state machine of the connection between the
48-6