23-Cluster Management Configuration

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Chapter 1  Cluster Management Configuration

When configuring cluster management, go to these sections for information you are interested in:

l           Cluster Management Overview

l           Cluster Configuration Task List

l           Configuring the Management Device

l           Configuring the Member Devices

l           Configuring Access Between the Management Device and Its Member Devices

l           Adding a Candidate Device to a Cluster

l           Configuring Advanced Cluster Functions

l           Displaying and Maintaining Cluster Management

l           Cluster Management Configuration Examples

1.1  Cluster Management Overview

1.1.1  Cluster Management Definition

A cluster is an aggregation of a group of communication devices. Cluster management is to implement management of large numbers of distributed network devices.

Cluster management is implemented through Huawei Group Management Protocol version 2 (HGMPv2). By employing HGMPv2, a network administrator can manage multiple devices using the public IP address of one device in a cluster. The device that configured with a public address and performs the management function is known as the management device and other managed devices are called member devices, which together form a cluster. Figure 1-1 illustrates a typical cluster implementation.

Figure 1-1 Network diagram for a cluster

Cluster management offers the following advantages:

l           Saving public IP address resource

l           Simplifying configuration and management tasks. By configuring a public IP address on the management device, you can configure and manage a group of member devices on the management device without the trouble of logging onto each device separately.

l           Providing topology discovery and display function, which is useful for network monitoring and debugging

l           Allowing simultaneous software upgrading and parameter configuring on multiple devices, free of topology and distance limitations

1.1.2  Roles in a Cluster

The devices in a cluster play different roles according to their different functions and status. You can specify the role a device plays. The following three roles exist in a cluster: management device, member device, and candidate device.

l           Management device: The device providing management interfaces for all devices in the cluster and the only device configured with a public IP address. Any configuration, management, and monitoring of the member devices in a cluster can only be implemented through the management device. When a device is specified as the management device, it collects Neighbor Discovery Protocol (NDP) and Neighbor Topology Discovery Protocol (NTDP) information to discover and define a candidate device.

l           Member device: The device being managed by the management device in a cluster.

l           Candidate device: A device that does not belong to any cluster but can be added to a cluster. Different from a member device, its topology information has been collected by the management device but it has not been added to the cluster.

Figure 1-2 Role change in a cluster

A device in a cluster changes its role according to the following rules:

l           A candidate device becomes a management device when you create a cluster on it. Note that a cluster must have one (and only one) management device. On becoming a management device, the device collects network topology information and tries to discover and determine candidate devices, which can then be added to the cluster through configuration.

l           A candidate device becomes a member device after being added to a cluster.

l           A member device becomes a candidate device after it is removed from the cluster.

l           A management device becomes a candidate device only after the cluster is removed.

1.1.3  How a Cluster Works

HGMPv2 consists of the following three protocols:

l           Neighbor Discovery Protocol (NDP)

l           Neighbor Topology Discovery Protocol (NTDP)

l           Cluster

A cluster configures and manages the devices in it through the above three protocols.

Cluster management involves topology information collection and the establishment and maintenance of a cluster. Topology information collection and cluster maintenance are independent from each other, with the former starting before the cluster is created:

l           All devices use NDP to collect the information of the directly connected neighbors, including their software version, host name, MAC address and port number.

l           The management device uses NTDP to collect the information of the devices within user-specified hops and the topology information of all devices and specify the candidate devices of the cluster.

l           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:

l           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.

l           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:

l           The management device periodically sends NTDP topology collection request from the NTDP-enabled ports.

l           Upon receiving the request, the device sends 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.

l           The adjacent device performs the same operation until the NTDP topology collection request is sent to all the devices within specified hops.

When the NTDP topology collection request is advertised in the network, large numbers of network devices receive the NTDP topology collection request and send NTDP topology collection response at the same time, which may cause congestion and the management device busyness. To avoid such case, the following methods can be used to control the speed of the NTDP topology collection request advertisement:

l           Upon receiving an NTDP topology collection request the device does not forward it, instead, it waits for a period of time and then forwards the NTDP topology collection request on the first NTDP-enabled port.

l           On the same device, except the first port, each NTDP-enabled port waits for a period of time and then forwards the NTDP topology collection request after the port before it sends the NTDP topology collection request.

III. 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 1-3.

Figure 1-3 Management/member device state change

l           After a cluster is created and a candidate device is added to the cluster and becomes a member device, the management device saves the state information of its member device and identifies it as Active. And the member device also saves its state information and identifies it as Active.

l           After a cluster is created, its member devices begin to send handshake packets first. The management device also sends handshake packets to the member devices at the same interval. Upon receiving the handshake packets from the other side, the management device or member device simply changes or remains its state as Active, without sending a response.

l           If the management device does not receive the handshake packets from a member device in an interval three times of the interval to send handshake packets, it changes the status of the member device from Active to Connect. Likewise, if a member device fails to receive the handshake packets from the management device in an interval three times of the interval to send handshake packets, the status of the member device will also be changed from Active to Connect.

l           If this management device, in information holdtime, receives the handshake or management packets from its member device which is in Connect state, it changes the state of its member device to Active; otherwise, it changes the state of its member device to Disconnect, in which case the management device considers its member device disconnected. If this member device, which is in Connect state, receives handshake or management packets from the management device in information holdtime, it changes its state to Active; otherwise, it changes its state to Disconnect.

l           If the communication between the management device and a member device is recovered, the member device which is in Disconnect state will be added to the cluster. After that, the state of the member device locally and on the management device will be changed to Active.

Besides, the member device informs the management device using handshake packets when there is a neighbor topology change.

IV. Management VLAN

The management VLAN limits the cluster management range. Through configuration of the management VLAN, the following functions can be implemented:

l           Management packets (including NDP, NTDP and handshake packets) are restricted within the management VLAN, therefore isolated from other packets, which enhances security.

l           The management device and the member devices communicate with each other through the management VLAN.

 For a cluster to work normally, you must set the packets from the management VLAN to pass the subtending ports (If a candidate device is connected to the management device through another candidate device, the ports connecting these two candidate devices are called subtending ports.) and the ports connecting the management device and the member/candidate devices. Therefore:

l           If the packets from the management VLAN cannot pass a port, the device connected with the port cannot be added to the cluster. Therefore, if the ports (including the subtending ports) connecting the management device and the member/candidate devices prohibit the packets from the management VLAN, you can set the packets from the management VLAN to pass the ports on candidate devices with the management VLAN auto-negotiation function.

l           Only when the default VLAN ID of the subtending ports and the ports connecting the management device and the member/candidate devices is that of the management VLAN can you set the packets without tags from the management VLAN to pass the ports; otherwise, only the packets with tags from the management VLAN can pass the ports.

Refer to VLAN Configuration for the introduction to VLAN.

1.2  Cluster Configuration Task List

Before configuring a cluster, you need to determine the roles and functions the devices play. You also need to configure the related functions, preparing for the communication between devices within the cluster.

Complete these tasks to configure a cluster:

Tasks

Remarks

Configuring the Management Device

Enabling NDP Globally and for Specific Ports

Optional

Configuring NDP Parameters

Optional

Enabling NTDP Globally and for Specific Ports

Optional

Configuring NTDP Parameters

Optional

Manually Collecting NTDP Information

Optional

Enabling the Cluster Function

Optional

Establishing a Cluster

Required

Configuring Communication Between the Management Device and the Member Devices Within a Cluster

Optional

Configuring Cluster Member Management

Optional

Configuring the Member Devices

Enabling NDP Globally and for Specific Ports

Optional

Enabling NTDP Globally and for Specific Ports

Optional

Manually Collecting NTDP Information

 

Enabling the Cluster Function

Optional

Deleting a Member Device from a Cluster

Optional

Configuring Access Between the Management Device and Its Member Devices

Optional

Adding a Candidate Device to a Cluster

Optional

Configuring Advanced Cluster Functions

Configuring Topology Management

Optional

Configuring Interaction for a Cluster

Optional

 

  Caution:

Disabling the NDP and NTDP functions on the management device and member devices after a cluster is created will not cause the cluster to be dismissed, but will influence the normal operation of the cluster.

 

1.3  Configuring the Management Device

1.3.1  Enabling NDP Globally and for Specific Ports

Follow these steps to enable NDP globally and for specific ports:

To do

Use the command

Remarks

Enter system view

system-view

Enable NDP globally

ndp enable

Optional

Enabled by default.

Enable the NDP feature for the port(s)

In system view

ndp enable interfaceinterface-list

Use either command

By default, NDP is enabled globally and also on all ports.

In Ethernet port view

interface interface-type interface-number

ndp enable

 

  Caution:

l      For NDP to work normally, you must enable NDP both globally and on the specified port.

l      If the subtending port or the port connecting the management device to a member/candidate device is a port of a member in an aggregation group, you must enable NDP on all member ports of the aggregation group at the same time. Otherwise, NDP will work abnormally.

l      You are recommended to disable NDP on the port which connects with the devices that do not need to join the cluster, preventing the management device from adding the device which needs not to join the cluster and collecting the topology information of this device.

 

1.3.2  Configuring NDP Parameters

Follow these steps to configure NDP parameters:

To do

Use the command

Remarks

Enter system view

system-view

Configure the period for the receiving devices to keep the NDP packets

ndp timer aging aging-time

Optional

180 seconds by default.

Configure the interval to send NDP packets

ndp timer hello hello-time

Optional

60 seconds by default.

 

  Caution:

The time for the receiving device to hold NDP packets cannot be shorter than the interval to send NDP packets; otherwise, the NDP table may become instable.

 

1.3.3  Enabling NTDP Globally and for Specific Ports

Follow these steps to enable NTDP globally and for specific ports:

To do

Use the command

Remarks

Enter system view

system-view

Enable NTDP globally

ntdp enable

Optional

Enabled by default

Enable NTDP for the port

interface interface-type interface-number

Optional

NTDP is enabled on all ports by default.

ntdp enable

 

  Caution:

l      For NTDP to work normally, you must enable NTDP both globally and on the specified port.

l      The NTDP function is mutually exclusive with the BPDU TUNNEL function under a port and you cannot enable them at the same time. For the detailed description of the BPDU TUNNEL function, refer to BPDU TUNNEL Configuration.

l      If the subtending port or the port connecting the management device to a member/candidate device is a port of a member in an aggregation group, you must enable NDP on all member ports of the aggregation group at the same time. Otherwise, NDP will work abnormally.

l      You are recommended to disable NDP on the port which connects with the devices that do not need to join the cluster, preventing the management device from adding the device which needs not to join the cluster and collecting the topology information of this device.

 

1.3.4  Configuring NTDP Parameters

Follow these steps to configure NTDP parameters:

To do

Use the command

Remarks

Enter system view

system-view

Configure the range within which topology information is to be collected

ntdp hop hop-value

Optional

By default, the hop range for topology collection is 3 hops.

Configure the interval to collect topology information

ntdp timer interval-time

Optional

1 minute by default.

Configure the delay to forward topology-collection request packets on the first port

ntdp timer hop-delay time

Optional

200 ms by default.

Configure the port delay to forward topology collection request

ntdp timer port-delay time

Optional

20 ms by default.

 

1.3.5  Manually Collecting NTDP Information

The management device collects topology information periodically after a cluster is created. In addition, you can configure to manually collect NTDP information to initiate NTDP information collection, thus managing and monitoring the device on real time, regardless of whether a cluster is created.

Follow these steps to configure to manually collect NTDP information:

To do…

Use the command…

Remarks

Manually collect NTDP information

ntdp explore

Required

 

1.3.6  Enabling the Cluster Function

To do

Use the command

Remarks

Enter system view

system-view

Enable the cluster function globally

cluster enable

Optional

Enabled by default.

 

1.3.7  Establishing a Cluster

Before establishing a cluster, you need to configure a private IP address pool for the devices to be added to the cluster. When a candidate device is added to a cluster, the management device assigns a private IP address to it for the candidate device to communicate with other devices in the cluster. This enables you to manage and maintain member devices in a cluster through the management device.

 

  Caution:

l      If the routing table of the management device is full when a cluster is created, that is, entries with the destination address as a candidate device cannot be added to the routing table, all candidate devices will be added to and removed from the cluster repeatedly.

l      If the routing table of a candidate device is full when the candidate device is added to the cluster, that is, entries with the destination address as the management device cannot be added to the routing table, the candidate device will be added to and removed from the cluster repeatedly.

 

  Caution:

l      You can only specify a management VLAN before establishing a cluster. After a device has been added to the cluster, you cannot modify the management VLAN. To change the management VLAN after the cluster is established, you should remove the cluster on the management device, re-specify the management VLAN and reestablish a cluster.

l      For the purpose of security, you are not recommended to configure the VLAN ID of the management VLAN as the default VLAN ID of the port connecting the management device to its member devices.

l      Only when the default VLAN ID of all subtending ports and the port connecting the management device to its member device is that of the management VLAN, can the packets without a tag from the management VLAN pass the ports. Otherwise, you must configure the packets from the management VLAN to pass these ports. For the configuration procedure, refer to VLAN Configuration in the Access Volume.

l      You must configure the IP address pool before establishing a cluster and configure it on the management device only. If a cluster has already been established, you are not allowed to change the IP address pool.

 

I. Manually establishing a cluster

Follow these steps to manually establish a cluster:

To do

Use the command

Remarks

Enter system view

system-view

Specify the management VLAN

management-vlan vlan-id

Optional

By default, VLAN 1 is the management VLAN.

Enter cluster view

cluster

Configure the private IP address range for member devices on a device which is to be configured as the management device

ip-pool administrator-ip-address { mask | mask-length }

Required

For a cluster to work normally, the IP addresses of the VLAN interfaces of the management device and member devices must not be in the same network segment as that of the cluster address pool.

Configure the current device as the management device and assign a name to it

build name

Required

By default, the device is not the management device.

 

II. Automatically establishing a cluster

In addition to establishing a cluster manually, you are also provided with the means to establish a cluster automatically. With only a few commands (as shown in the table below) on the management device, you can let the system automatically build a cluster.

During the process, you will first be asked to enter a name for the cluster you want to establish, the system then lists all the candidate devices within your predefined hop counts and starts to automatically add them to the cluster.

You can use <Ctrl+C> anytime during the adding process to exit cluster auto-building. However, this will only stop adding new devices into the cluster, and devices already added in the cluster are not removed.

Follow these steps to automatically establish a cluster:

To do

Use the command

Remarks

Enter system view

system-view

Specify the management VLAN

management-vlan vlan-id

Optional

By default, VLAN 1 is the management VLAN.

Enter cluster view

cluster

Configure the private IP address range for member devices on a device which is to be configured as the management device

ip-pool administrator-ip-address { mask | mask-length }

Required

For a cluster to work normally, the IP addresses of the VLAN interfaces of the management device and member devices must not be in the same network segment as the cluster address pool.

Establish a cluster automatically

auto-build [ recover ]

Required

 

1.3.8  Configuring Communication Between the Management Device and the Member Devices Within a Cluster

In a cluster, the management device and member devices communicate by sending handshake packets to maintain connection between them. You can configure interval of sending handshake packets and the holdtime of a device on the management device. This configuration applies to all member devices within the cluster.

Follow these steps to configure communication between the management device and the member devices within a cluster:

To do

Use the command

Remarks

Enter system view

system-view

Configure the interval to send handshake packets

timer interval-time

Optional

10 seconds by default

Configure the holdtime of a device

holdtime seconds

Optional

60 seconds by default

 

1.3.9  Configuring Cluster Member Management

I. Adding/Removing a member device

You can manually add a candidate device to a cluster, or remove a member device from a cluster. These operations must be done through the management device, otherwise you will be prompted with an error message.

Follow these steps to add/remove a member device:

To do

Use the command

Remarks

Enter system view

system-view

Enter cluster view

cluster

Add a candidate device to the cluster

add-member [ member-number ] mac-address mac-address [ password password ]

Optional

Remove a member device from the cluster

delete-member member-number [ to-black-list ]

Required

 

II. Rebooting a member device

Communication between the management and member devices may be interrupted due to some configuration errors. Through the remote control function of member devices, you can control them remotely on the management device. For example, you can reboot a member device tha