H3C Technologies H3C S3600 Series Switches - Manual (Page 810)

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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. Figure 1-3 illustrates the state machine of the connection between the
management device and a member device.
Figure 1-3 State machine of the connection between the management device and a member device
Receives the
handshake or
management
packets Fails to receive
handshake
packets in three
consecutive
intervals
State holdtime exceeds
the specified value
Disconnect state
is recovered
Active
Connect Disconnect
z After a cluster is created and a candidate device is added to the cluster as a member device, both
the management device and the member device store the state information of the member device
and mark the member device as Active.
z The management device and the member devices exchange handshake packets periodically. Note
that the handshake packets exchanged keep the states of the member devices to be Active and
are not responded.
z If the management device does not receive a handshake packet from a member device after a
period three times of the interval to send handshake packets, it changes the state of the member
device from Active to Connect. Likewise, if a member device fails to receive a handshake packet
from the management device after a period three times of the interval to send handshake packets,
the state of the member device will also be changed from Active to Connect.
z If the management device receives a handshake packet or management packet from a member
device that is in Connect state within the information holdtime, it changes the state of the member