H3C S3610-28P Operation Manual page 1134

Operation Manual – Cluster Management
H3C S3610&S5510 Series Ethernet Switches
The management device adds or deletes a member device and modifies cluster
management configuration according to the candidate device information
collected through NTDP.
I. Introduction to NDP
NDP is used to discover the information about directly connected neighbors, including
the device name, software version, and connecting port of the adjacent devices. NDP
works in the following ways:
A device running NDP periodically sends NDP packets to its neighbors. An NDP
packet carries NDP information (including the device name, software version, and
connecting port, etc.) and the holdtime, which indicates how long the receiving
devices will keep the NDP information. At the same time, the device also receives
but does not forward the NDP packets from its neighbors.
A device running NDP stores and maintains an NDP table. The device creates an
entry in the NDP table for each neighbor. If a new neighbor is found, meaning the
device receives an NDP packet sent by the neighbor for the first time, the device
adds an entry in the NDP table. When another NDP packet is received, if the NDP
information carried in the NDP packet is different from the stored information, the
corresponding entry in the NDP table is updated; otherwise, only the holdtime of
the entry is updated. If no NDP information from the neighbor is received within the
holdtime, the corresponding entry is removed from the NDP table.
NDP runs on the data link layer, and therefore supports different network layer
protocols.
II. Introduction to NTDP
NTDP is a protocol used to collect network topology information. NTDP provides
information required for cluster management: it collects topology information about the
devices within the specified hop count, to identify candidate devices for a cluster.
Based on the neighbor information stored in the neighbor table maintained by NDP,
NTDP on the management device advertises NTDP topology collection requests to
collect the NDP information of each device in a specific network range as well as the
connection information of all its neighbors. The information collected will be used by the
management device or the network management software to implement required
functions.
When a member device detects a change on its neighbors through its NDP table, it
informs the management device through handshake packets. Then the management
device triggers its NTDP to perform specific topology collection, so that its NTDP can
discover topology changes timely.
The management device collects topology information periodically. You can also
administratively launch a topology information collection with commands. The process
of topology information collection is as follows:
Chapter 1 Cluster Management Configuration
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