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

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NDP runs on the data link layer and supports different network layer protocols.
About NTDP
NTDP provides information required for cluster management. It collects topology information about the
devices within the specified hop count. 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 all the devices 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
collect specific topology information, 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. The process of topology information collection is as follows:
• The management device periodically sends NTDP topology-collection request from the
NTDP-enabled ports.
• Upon receiving the request, the device sends an NTDP topology-collection response to the
management device, copies this response packet on the NTDP-enabled port and sends it to the
adjacent device. Topology-collection response includes the basic information of the NDP-enabled
device and NDP information of all adjacent devices.
• The adjacent device performs the same operation until the NTDP topology-collection request is sent
to all the devices within specified hops.
To avoid concurrent responses to an NTDP topology-collection request causing congestion and deny of
service on the management device, a delay mechanism was introduced. You configure the delay
parameters for NTDP on the management device. As a result:
• Each requested device waits for a period of time before forwarding an NTDP topology-collection
request on the first NTDP-enabled port.
• After the first NTDP-enabled port forwards the request, all other NTDP-enabled ports on the
requested device forward the request in turn at a specific interval.
Cluster management maintenance
1. Adding a candidate device to a cluster
You should specify the management device before creating a cluster. The management device
discovers and defines a candidate device through NDP and NTDP protocols. The candidate
device can be automatically or manually added to the cluster.
After the candidate device is added to the cluster, it can obtain the member number assigned by
the management device and the private IP address used for cluster management.
2. Communication within a cluster
In a cluster the management device communicates with its member devices by sending handshake
packets to maintain connection between them. The management/member device state change is
shown in Figure 26.