Chapter 1 Cluster
The cluster function is implemented through
Huawei group management protocol version 2 (HGMP V2). With HGMP V2, a network administrator
can manage multiple switches through the public IP address of a switch known as
a management device. The managed switches under the management device are called
member devices. The management device and the member devices together compose a
cluster. Normally, member devices do not have public IP addresses, but you can
manage and maintain them through the management device, which can redirect your
management and maintenance operations to their intended destinations. Figure 1-1 illustrates a typical cluster application.
Figure 1-1 Cluster illustration
HGMP V2 has the following advantages:
l
It eases the configuration and management of multiple
switches: You just need to configure a public IP address for the management
device instead of for all the devices in the cluster; and then you can configure
and manage all the member devices through the management device without the
need to log onto them one by one.
l
It provides the topology discovery and display function,
which assists in monitoring and maintaining the network.
l
It allows you to configure and upgrade multiple
switches at the same time.
l
It enables you to manage your remotely devices
conveniently regardless of network topology and physical distance.
l
It saves IP address resource.
HGMP V2 comprises the following three
protocols:
l
Neighbor discovery protocol (NDP): This protocol
is able to discover directly connected neighbor devices and provide information
about those devices, including device type, software/hardware version,
connecting port, and some other information such as device ID, port full/half duplex
mode, product version, and Boot ROM version.
l
Neighbor topology discovery protocol (NTDP): This
protocol is able to discover network topology and provide network topology information.
It collects device and device connection information in your network and allows
you to adjust the range of topology discovery.
l
Cluster management protocol: This protocol
provides the member recognition and member management functions. It works in
conjunction with the network management software to implement large-scale network
management. Member recognition means that the management device locates and recognizes
each member in the cluster so that it can redirects configuration and
management commands to the its members. Member management means that the management
device manages such events as adding a member and removing a member, and such
cluster parameter settings as handshake interval, cluster management VLAN and shared
FTP server settings.
Cluster-related configurations will be
described in later sections.
NDP is a protocol used to discover adjacent
nodes and provide information about them. NDP operates at the data link layer, and
therefore it supports different network layer protocols.
NDP is able to discover directly connected
neighbors and provide the following neighbor information: device type,
software/hardware version, and connecting port. In addition, it may provide the
following neighbor information: device ID, port full/half duplex mode, product
version, Boot ROM version and so on.
An NDP-enabled device maintains an NDP neighbor
table. Each entry in the NDP table can automatically ages out. You can also
clear the current NDP information manually to have neighbor information
collected again.
An NDP-enabled device regularly broadcasts
NDP packet through all its active ports. An NDP packet carries a holdtime
field, which indicates how long the receiving devices will keep the NDP packet data.
The receiving devices store the information carried in the NDP packet into the
NDP table but do not forward the NDP packet. When they receive another NDP
packet, if the information carried in the packet is different from the stored
one, the corresponding entry in the NDP table is updated, otherwise only the holdtime
of the entry is updated.
NTDP is a protocol used to collect network topology information.
NTDP provides information required for cluster management: it collects topology
information about the switches within the specified hop count, so as to provide
the information of which devices can be added to 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 finds any change on
its neighbors through its NDP table, it informs the management device through
handshake packets, and the management device triggers its NTDP to perform
specific topology collection, so that its NTDP can discover topology changes in
real time.
To implement NTDP,
you need to enable NTDP globally and on specific ports on both management
device and member/candidate devices, and configure NTDP parameters on only management
device. You need not configure NTDP parameters on member/candidate devices
because they adopt NTDP parameter settings delivered from the management device
when NTDP is running.
A cluster must have one and only one
management device. Note the following when creating a
cluster:
l
You need to designate a management device for the
cluster. The management device of a cluster is the portal of the cluster. That
is, any operations from outside the network intended for the member devices of the
cluster, such as accessing, configuring, managing, and monitoring, can only be
implemented through the management device.
l
The management device of the cluster recognizes
and controls all the member devices in the cluster, no matter where they are
located in the network and how they are connected.
l
The management device collects topology
information about all member/candidate devices to provide useful information
for you to establish the cluster.
l
By collecting NDP/NTDP information, the
management device learns network topology, so as to manage and monitor network devices.
l
Before performing any cluster-related configuration
task, you must first enable the cluster function.
On the management device, you need to enable the cluster function
and configure cluster parameters. On the member/candidate devices, however, you
only need to enable the cluster function so that they can be managed by the
management device.
Additionally, on the management device, you
can configure the FTP server, TFTP server, logging host and SNMP host to be
shared by the whole cluster. When a member device in the cluster communicates
with an external server, the member device first transmits data to the
management device, which then forwards the data to the external server. The
management device is the default shared FTP/TFTP server for the cluster; it
serves as the shared FTP/TFTP server when no shared FTP/TFTP server is
configured for the cluster.
The most important function of clusters is
to work in conjunction with the network management software to implement
large-scale network management. You can specify a network management interface on
the management device of a cluster, through which the network administrator can
log onto the management device to manage the devices in the cluster.
l
By default, the management VLAN interface is
used as the network management interface.
l
There is only one network management interface
on a management device; any newly configured network management interface will overwrite
the old one.
From the point of view of a cluster, switches
may play different roles, which depend on their functionality and status. You
can specify the role of a switch, or change the role of a switch following some
specific rules.
For a cluster, a switch may play one of the
three roles: management device, member device, and candidate device.
Table 1-1
Switch roles for a cluster
|
Role
|
Configuration
|
Functionality
|
|
Management device
|
l The management device is configured with a public IP address.
l
You can issue management commands to the
management device across the Internet, and the management device will further
process your commands.
|
l The management device provides a management interface to all
switches in the cluster.
l It manages member devices by redirecting commands. That is, it forwards
commands to their intended member devices for processing.
l
It has the following functions: neighbor
discovery, topology collection, cluster management and cluster status
maintenance, and supports FTP Server and SNMP proxies.
|
|
Member device
|
Normally, a member device is not
configured with a public IP address.
|
l A member device acts as a member in the cluster.
l
It has the following functions: neighbor
discovery, accepting the management of the management device, running
commands forwarded by proxies and reporting failures/logs
|
|
Candidate device
|
Normally, a candidate device is not
configured with a public IP address.
|
A candidate device is a switch that does
not belong to any cluster; it has cluster capability and can be added to a
cluster.
|
A switch can change from one role to
another according to the following rules:
Figure
1-2 Role switching rules
l
A candidate device becomes a management device
after you designate it as the management device of a cluster (you can do this
by building a cluster on the device). Each cluster must have one and only one
management device. After you specify the management device of a cluster, the
management device discovers and determines candidate devices (by collecting
NDP/NTDP information), which you can then add into the cluster through manual
configuration.
l
A candidate device becomes a member device after
being added to a cluster.
l
A member device becomes a candidate device after
being removed from the cluster.
l
The management device becomes a candidate device
only after you remove the cluster.
After a cluster is
set up on an S3100-52P switch, the switch will collect the topology information
of the network at the topology collection interval you set and automatically add
the candidate devices it discovers into the cluster. As a result, if the
topology collection interval is too short (the default interval is 1 minute),
the switches acting as candidate devices will not keep in candidate state for a
long time – they will change to member devices within a short time. If you
do not want the candidate switches to be automatically added into the cluster,
you can set the topology collection interval to 0 (by using the ntdp timer
command), which specifies not to perform topology collection periodically.
Table 1-2
Management device cluster configuration tasks
To reduce the risk of being attacked by malicious users against
opened socket and enhance switch security, the S3100-52P Ethernet switches
provide the following functions, so that a cluster socket is opened only when
it is needed:
l
Opening UDP port 40000 (used for cluster) only when
the cluster function is implemented,
l
Closing UDP port 40000 at the same time when the
cluster function is closed.
On the management
device, the preceding functions are implemented as follows:
l
When you create a cluster by using the build
or auto-build command, UDP port 40000 is opened at the same time.
l
When you remove a cluster by using the undo build
or undo cluster enable command, UDP port 40000 is closed at the same
time.
Table 1-3 Enable NDP globally and on specific ports
|
Operation
|
Command
|
Description
|
|
Enter system view
|
system-view
|
—
|
|
Enable NDP globally
|
ndp enable
|
Required
By default, NDP is enabled globally.
|
|
Enable NDP on specified Ethernet ports
|
In system view
|
ndp enable interface port-list
|
You must choose one of the two ways.
By default, NDP is enabled on a port.
|
|
In Ethernet port view
|
Enter Ethernet port view
|
interface interface-type interface-number
|
|
Enable NDP on the port
|
ndp enable
|
Table 1-4 Configure NDP-related
parameters
|
Operation
|
Command
|
Description
|
|
Enter system view
|
system-view
|
—
|
|
Configure the holdtime of NDP information
|
ndp timer aging aging-in-seconds
|
Optional
By default, the holdtime of NDP information
is 180 seconds.
|
|
Configure the interval to send NDP packets
|
ndp timer hello seconds
|
Optional
By default, the interval to send NDP
packets is 60 seconds.
|
Table 1-5 Enable NTDP globally and on a specific port
|
Operation
|
Command
|
Description
|
|
Enter system view
|
system-view
|
—
|
|
Enable NTDP globally
|
ntdp enable
|
Required
|
|
Enter
Ethernet port view
|
interface
interface-type interface-number
|
—
|
|
Enable NTDP on the Ethernet port
|
ntdp enable
|
Required
|
Table 1-6 Configure NTDP-related
parameters
|
Operation
|
Command
|
Description
|
|
Enter system view
|
system-view
|
—
|
|
Configure the range to collect topology information
|
ntdp hop hop-value
|
Optional
By default, the system collects topology
information from the devices within three hops.
|
|
Configure the device forward delay of
topology collection requests
|
ntdp timer hop-delay time
|
Optional
By default, the device forward delay is
200 ms.
|
|
Configure the port forward delay of
topology collection requests
|
ntdp timer port-delay time
|
Optional
By default, the port forward delay is 20
ms.
|
|
Configure the interval to collect topology
information periodically
|
ntdp timer interval-in-minutes
|
Optional
By default, the topology collection interval
is one minute.
|
|
Quit system view
|
quit
|
—
|
|
Start topology collection
|
ntdp explore
|
Optional
|
Table 1-7 Enable the cluster function
|
Operation
|
Command
|
Description
|
|
Enter system view
|
system-view
|
—
|
|
Enable the cluster function globally
|
cluster enable
|
Optional
By default, the cluster function is enabled.
|
I. Manually building a cluster and
configuring cluster parameters
Table 1-8 Manually build a cluster and configure
cluster parameters
|
Operation
|
Command
|
Description
|
|
Enter system view
|
system-view
|
—
|
|
Specify the management VLAN
|
management-vlan vlan-id
|
Required
By default, VLAN 1 is used as the
management VLAN.
|
|
Enter cluster view
|
cluster
|
—
|
|
Configure a IP address pool for the
cluster
|
ip-pool administrator-ip-address
{ ip-mask | ip-mask-length }
|
Required
|
|
Build a cluster
|
build name
|
Required
name: cluster
name.
|
|
Configure a multicast MAC address for the
cluster
|
cluster-mac H-H-H
|
Optional
By default, the cluster multicast MAC
address is 0180-C200-000A.
|
|
Set the interval for the management
device to send multicast packets
|
cluster-mac syn-interval time-interval
|
Optional
By default, the interval to send
multicast packets is one minutes.
|
|
Set the holdtime of member switches
|
holdtime seconds
|
Optional
By default, the holdtime is 60 seconds.
|
|
Set the interval to send handshake
packets
|
timer interval
|
Optional
By default, the interval to send
handshake packets is 10 seconds.
|
|
Quit cluster view
|
quit
|
—
|
II. Starting automatic cluster
building
Table 1-9 Start automatic cluster building
|
Operation
|
Command
|
Description
|
|
Enter system view
|
system-view
|
—
|
|
Enter cluster view
|
cluster
|
—
|
|
Configure the cluster IP address range
|
ip-pool administrator-ip-address
{ ip-mask | ip-mask-length }
|
Required
|
|
Start automatic cluster building
|
auto-build [ recover ]
|
Required
Follow prompts to build a cluster.
|
Table
1-10 Configure interaction for the cluster
|
Operation
|
Command
|
Description
|
|
Enter system view
|
system-view
|
—
|
|
Enter cluster view
|
cluster
|
Required
|
|
Configure a shared FTP server for the cluster
|
ftp-server ip-address
|
Optional
By default, the management device acts as
the shared FTP server.
|
|
Configure a shared TFTP server for the cluster
|
tftp-server ip-address
|
Optional
By default, no shared TFTP server is
configured.
|
|
Configure a shared logging host for the cluster
|
logging-host ip-address
|
Optional
By default, no shared logging host is
configured.
|
|
Configure a shared SNMP host for the cluster
|
snmp-host ip-address
|
Optional
By default, no shared SNMP host is
configured.
|
I. Configuration prerequisites
l
The cluster switches are properly connected;
l
The shared servers are properly connected to the
management switch.
II. Configuration procedure
Table
1-11 Configure NM interface for the cluster
|
Operation
|
Command
|
Description
|
|
Enter
system view
|
system-view
|
—
|
|
Enter
cluster view
|
cluster
|
Required
|
|
Configure
the network management (NM) interface for the cluster
|
nm-interface Vlan-interface vlan-id
|
Optional
By
default, the management VLAN interface is used as the NM interface.
|
Table
1-12 Member device Cluster configuration tasks
To reduce the risk of being attacked by malicious users against
opened socket and enhance switch security, the S3100-52P Ethernet switches
provide the following functions, so that a cluster socket is opened only when
it is needed:
l
Opening UDP port 40000 (used for cluster) only
when the cluster function is implemented,
l
Closing UDP port 40000 at the same time when the
cluster function is closed.
On member devices, the preceding functions are implemented as follows:
l
When you execute the add-member command
on the management device to add a candidate device to a cluster, the candidate
device changes to a member device and its UDP port 40000 is opened at the same
time.
l
When you execute the auto-build command
on the management device to have the system automatically add candidate devices
to a cluster, the candidate devices change to member devices and their UDP port
40000 is opened at the same time.
l
When you execute the administrator-address
command on a device, the device's UDP port 40000 is opened at the same time.
l
When you execute the delete-member
command on the management device to remove a member device from a cluster, the
member device's UDP port 40000 is closed at the same time.
l
When you execute the undo build command
on the management device to remove a cluster, UDP port 40000 of all the member
devices in the cluster is closed at the same time.
l
When you execute the undo
administrator-address command on a member device, UDP port 40000 of the member
device is closed at the same time.
Table 1-13 Enable NDP globally and on specific ports
|
Operation
|
Command
|
Description
|
|
Enter
system view
|
system-view
|
—
|
|
Enable NDP
globally
|
ndp
enable
|
Required
|
|
Enable NDP
on specified ports
|
In system
view
|
ndp
enable interface port-list
|
Required
You can
choose to enable NDP on some ports in system view or enable NDP on a port in
Ethernet port view.
|
|
In
Ethernet port view
|
Enter
Ethernet port view
|
interface
interface-type interface-number
|
|
Enable NDP
on the port
|
ndp
enable
|
Table 1-14 Enable NTDP globally and a specific port
|
Operation
|
Command
|
Description
|
|
Enter system view
|
system-view
|
—
|
|
Enable NTDP globally
|
ntdp enable
|
Required
|
|
Enter Ethernet port view
|
interface interface-type interface-number
|
—
|
|
Enable NTDP on the port
|
ntdp enable
|
Required
|
Table
1-15 Enable the cluster function
