HP TruCluster Server V5.1B-1, Specification

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Supported LAN Supported LAN Supported LAN Supported LAN
Interconnect Hardware
Interconnect Hardware Interconnect Hardware Interconnect Hardware
Use of dedicated LAN is supported for use as a cluster interconnect. A LAN interconnect must be private to cluster members.
As long as any packet that is transmitted by a cluster member's interconnect adapter can only be received by interconnect
adapters of other members of the same cluster, the interconnect meets the privacy requirement.
A LAN interconnect can be a direct connection between two cluster members or can employ hubs or switches. In general,
any Ethernet adapter, switch, or hub that works in a standard LAN at 100 Mbps or 1000 Mbps should work within a LAN
interconnect. (Adapters on combo cards such as the KZPCM, DEPVD, and the DEPVZ are not supported.) Check the
supported options list (at
http://h18002.www1.hp.com/alphaserver/products/options.html ) for the hardware platform in
question to verify if the DEGXA-SA/TA is supported for LAN interconnect. Fiber Distributed Data Interface (FDDI), ATM LAN
Emulation (LANE), and 10 Mbps Ethernet are not supported.
Although hubs and switches are interchangeable in most LAN interconnect configurations, switches are recommended for
performance and scalability. Most hubs run in half-duplex mode and do not detect network collisions, so their use in a LAN
interconnect may limit cluster performance. Overall, using a switch, rather than a hub, provides greater scalability for
clusters with three or more members.
Adapters and switch ports must be configured compatibly with respect to speed (100 Mbps or 1000 Mbps) and operational
mode (full-duplex). A maximum of three hops is allowed between cluster members, where a hop means passing from a
system, switch, hub, or router, to another system, switch, hub, or router. That is, any combination of up to two hubs,
switches, or routers is supported between two cluster members. You must not introduce unacceptable latencies by using, for
example, a satellite uplink or a wide area network (WAN) in the path between two components of a LAN interconnect.
A fully redundant LAN interconnect configuration employs two or more Ethernet adapters in a NetRAIN set on each
member, with redundant wiring to two or more switches interlinked by two crossover cables. These Ethernet switches must be
capable of one of the follow mechanisms for managing traffic across parallel inter-switch links: link aggregation (also
known as port trunking), resilient links, or per-port-enabled spanning tree algorithm.
QuickSpecs
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Optional Software
DA - 11444 Worldwide — Version 4 — December 8, 2003 Page 13