3Com Switch 7757, Руководство по настройке

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704 C
HAPTER
63: C
LUSTER
a specific member device on the management device instead of logging into it
in advance.
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Functions of topology discovery and display provided, which assist network
monitoring and debugging
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Software upgrading and parameter configuring can be performed
simultaneously on multiple switches.
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Free of topology and distance limitations
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Saving IP address resource
Switch Clustering V2 is comprised of the following three protocols:
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Neighbor discovery protocol (NDP): Switch Clustering V2 implements NDP to
discover the information about the directly connected neighbor devices,
including device type, software/hardware version, connecting port and so on.
The information such as device ID, port mode (duplex or half duplex), product
version, and BootROM version can also be given.
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Neighbor topology discovery protocol (NTDP): Switch Clustering V2
implements NTDP to collect the information about the network topology,
including the device connections and the device information in the network.
The hop range for topology discovery can be adjusted manually.
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Cluster management protocol: The cluster management protocol provides the
member recognition and member management function. It can also perform
large-scaled device management together with the network administrator.
Member recognition means that the management device recognizes each
member in the cluster through locating each member and then distributes the
configuration and management commands to members. Member
management means to manage the following events through the
management device, including adding a member, removing a member, and the
member’s authentication on the management device. Member management
also manages the cluster parameters including interval of sending handshake
packets, management VLAN of the cluster, public FTP server of the cluster.
Cluster-related configurations are described in the following sections.
Introduction to NDP NDP is the protocol for discovering the information about the adjacent nodes. NDP
operates on the data link layer, so it supports different network layer protocols.
NDP is used to discover the information about directly connected neighbors,
including the device type, software/hardware version, and connecting port of the
adjacent devices. It can also provide the information concerning device ID, port
simplex/duplex status, product version, BootROM version and so on.
An NDP-enabled device maintains an NDP information table. Each entry in an NDP
table ages with time. You can also clear the current NDP information manually to
have adjacent information collected again.
An NDP-enabled device broadcasts NDP packets regularly to all ports in up state.
An NDP packet carries the holdtime field, which indicates the period for the
receiving devices to keep the NDP data. Receiving devices only store the
information carried in the received NDP packets rather than forward them. The
corresponding data entry in the NDP table is updated when the received