Operation Manual – Stack-Cluster
H3C S3100 Series Ethernet Switches
Chapter 2 Cluster
2-7
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 2-3
illustrates the 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
Figure 2-3
State machine of the connection between the management device and a
member device
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 device to Active; otherwise, it changes the state
of the member device (in Connect state) to Disconnect, in which case the
management device considers the member device disconnected. Likewise, if this
member device, which is in Connect state, receives a handshake packet or
management packet from the management device within the information holdtime,
it changes its state to Active; otherwise, it changes its state to Disconnect.