Operation Manual – Stack-ClusterH3C S3100 Series Ethernet Switches Chapter 2 Cluster2-7through NDP and NTDP, and adds them to the cluster. You can also add candidatedevices to a cluster manually.After a candidate device is added to a cluster, the management device assigns amember number and a private IP address (used for cluster management) to it.2) Communications within a clusterIn a cluster, the management device maintains the connections to the member devicesthrough handshake packets. Figure 2-3 illustrates the state machine of the connectionbetween the management device and a member device.Receives thehandshake ormanagementpacketsFails to receivehandshakepackets in threeconsecutiveintervalsState holdtime exceedsthe specified valueDisconnect stateis recoveredActiveConnect DisconnectFigure 2-3 State machine of the connection between the management device and amember devicez After a cluster is created and a candidate device is added to the cluster as amember device, both the management device and the member device store thestate information of the member device and mark the member device as Active.z The management device and the member devices exchange handshake packetsperiodically. Note that the handshake packets exchanged keep the states of themember devices to be Active and are not responded.z If the management device does not receive a handshake packet from a memberdevice after a period three times of the interval to send handshake packets, itchanges the state of the member device from Active to Connect. Likewise, if amember device fails to receive a handshake packet from the management deviceafter a period three times of the interval to send handshake packets, the state ofthe member device will also be changed from Active to Connect.z If the management device receives a handshake packet or management packetfrom a member device that is in Connect state within the information holdtime, itchanges the state of the member device to Active; otherwise, it changes the stateof the member device (in Connect state) to Disconnect, in which case themanagement device considers the member device disconnected. Likewise, if thismember device, which is in Connect state, receives a handshake packet ormanagement packet from the management device within the information holdtime,it changes its state to Active; otherwise, it changes its state to Disconnect.
