R2511-HP MSR Router Series Network Management and Monitoring Configuration Guide(V5)

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Figure 26 Management/member device state change
A cluster manages the state of its member devices as follows:
• After a candidate device is added to the cluster and becomes a member device, the management
device saves its state information and identifies it as Active. The member device also saves its state
information and identifies itself as Active.
• The management device and member devices send handshake packets. Upon receiving the
handshake packets, the management device or a member device keeps its state as Active without
sending a response.
• If the management device does not receive handshake packets from a member device within a
period that is three times the handshake interval, it changes the status of the member device from
Active to Connect. Likewise, if a member device fails to receive handshake packets within a period
that is three times the handshake interval, its state changes from Active to Connect.
• During the information holdtime, if the management device receives handshake or management
packets from a member device that is in Connect state, it changes the state of the member device
to Active. Otherwise, it considers the member device to be disconnected, and changes the state of
the member device to Disconnect.
• During the information holdtime, a member device in Connect state changes its state to Active if it
receives handshake or management packets from the management device. Otherwise, it changes
its state to Disconnect.
• When the communication between the management device and a member device is recovered, the
member device is added to the cluster and its state changes from Disconnect to Active on itself and
the management device.
• Besides, a member device sends handshake packets to inform the management device of neighbor
topology changes.
Management VLAN
Management VLAN limits the cluster boundaries. All cluster control packets, including NDP, NTDP, and
handshake packets between the management device and member devices are restricted within the
cluster management VLAN.
To assign a candidate to a cluster, make sure all ports on the path from the candidate device to the
management device are in the management VLAN. If not, the candidate device cannot join the cluster.
You can manually assign ports to the management VLAN or use the management VLAN autonegotiation
function to enable automatic VLAN assignment on the management device.