82598EB Datasheet, PDF (419/596 Pages) Intel Corporation – Intel® 82598EB 10 Gigabit Ethernet Controller Datasheet

Intel^® 82598EB 10 GbE Controller - SMBus Pass-Through Interface
5.3
SMBus Pass-Through Interface
SMBus is the system management bus defined by Intel® Corporation in 1995. It is used in personal
computers and servers for low-speed system management communications. The SMBus interface is
one of two pass-through interfaces available in 82598EB controller.
This section describes how the SMBus interface in the 82598EB operates in pass-through mode.
5.3.1 General
The SMBus sideband interface includes the standard SMBus commands used for assigning a slave
address and gathering device information as well as Intel proprietary commands used specifically for
the pass-through interface.
5.3.2 Pass-Through Capabilities
This section details the specific manageability capabilities the 82598EB provides while in SMBus mode.
The pass-through traffic is carried by the sideband interface as described in Section 5.1.
When operating in SMBus mode, in addition to exposing a communication channel to the LAN for the
BMC, 82598EB provides the following manageability services to the BMC:
• ARP handling - The 82598EB can be programmed to auto-ARP replying for ARP request packets to
reduce the traffic over the BMC interconnect. See Section 5.3.3.2 for details.
• Teaming and fail-over - The 82598EB can be configured to one of several teaming and fail-over
configurations (See Section 5.3.11.1):
—No-teaming - The 82598EB dual LAN ports act independently of each other and no fail-over is
provided by 82598EB. The BMC is responsible for teaming and fail-over.
—Teaming - The 82598EB is configured to provide fail-over capabilities, such that manageability
traffic is routed to an active port if any of the ports fail. Several modes of operation are
provided.
Note: These services are not available in NC-SI mode.
5.3.2.1 Packet Filtering
Since the host OS and the BMC both use 82598EB Ethernet controller to send and receive Ethernet
traffic, there needs to be a mechanism by which incoming Ethernet packets can be identified as those
that should be sent to the BMC rather than the host OS.
In order to determine the types of traffic that is forwarded to the BMC over the sideband interface,
82598EB supports a manageability receive filtering mechanism. This mechanism is used to decide if a
received packet should be forwarded to the BMC or to the host.
The following is a list of the filtering capabilities available for the SMBus interface with 82598EB:
• RMCP/RMCP+ ports
• Flexible UDP/TCP port filters
• 128-byte flexible filters
• VLAN
• IPv4 address
• IPv6 address
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