Dell Broadcom NetXtreme Family of Adapters - Manual (Page 106)

Broadcom Teaming Services: Broadcom NetXtreme II® Network Adapter User Guide
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information for a given TCP connection.
Because Broadcom's SLB modes can control how both outbound and inbound packets are balanced across the adapters, the
SLB modes are capable of ensuring that all offloaded TCP traffic for a given TCP connection goes in and out of a particular
adapter. This architectural feature allows the SLB modes to also support load-balancing on adapters that have TOE enabled,
since BASP is able to steer traffic on a particular TCP connection to the adapter hardware that contains offloaded state
information for that TCP connection. BASP can simultaneously use TCP offload in conjunction with the SLB modes of teaming.
Other teaming modes (Generic Trunking or Link Aggregation) can still be used on TOE capable devices, but if those other
modes are enabled the TOE feature is disabled.
Since the TOE offloaded state is stored in only one member of a team, it might not be intuitive as to how BASP can support
failover on TOE teams. When a TOE connection has been offloaded to a given adapter, and if that network interface fails in
some way (that is, it loses its network link due to a cable disconnection), then BASP will detect the error and force an upload
of the offloaded TCP state for each previously offloaded TCP connection on that adapter to the host. Once all of the previously
offloaded state has been uploaded, BASP will rebalance the recently uploaded TCP connections and offload those connections
evenly to the remaining members of the team. Basically, if there is a failure on a TOE-enabled adapter, any TCP connections
that had been offloaded to that adapter are migrated to the remaining nonfailed members in the team.
For Broadcom NetXtreme II adapters, there are no specific setup requirements in order for TCP Offload Engine (TOE) to work
with BASP. Once the individual adapters are configured to enable TOE, they can be added to a team and the offload is
transparent to BASP. For information on configuring TOE, see
Viewing and Configuring Resource Reservations .
Limitations of Teaming with Offloading
TOE is enabled for a team only when all of the members support and are configured for TOE.
TOE is only supported on SLB-type teams.
Each virtual BASP device advertises 1024 offload connections. If the number of virtual BASP devices in a team exceeds
the number of active physical members, the maximum offload connections for each virtual device may be lower.
Software Components
Teaming is implemented via an NDIS intermediate driver in the Windows Operating System environment. This software
component works with the miniport driver, the NDIS layer, and the protocol stack to enable the teaming architecture (see
Figure 2 ). The miniport driver controls the host LAN controller directly to enable functions such as sends, receives, and
interrupt processing. The intermediate driver fits between the miniport driver and the protocol layer multiplexing several
miniport driver instances, and creating a virtual adapter that looks like a single adapter to the NDIS layer. NDIS provides a
set of library functions to enable the communications between either miniport drivers or intermediate drivers and the protocol
stack. The protocol stack implements IP, IPX and ARP. A protocol address such as an IP address is assigned to each miniport
device instance, but when an Intermediate driver is installed, the protocol address is assigned to the virtual team adapter and
not to the individual miniport devices that make up the team.
The Broadcom supplied teaming support is provided by three individual software components that work together and are
supported as a package. When one component is upgraded, all the other components must be upgraded to the supported
versions.
Table 3 describes the four software components and their associated files for supported operating systems.
Table 3: Broadcom Teaming Software Component
Software
Component
Broadcom Name
Network Adapter/Operating
System
System
Architecture
Windows File
Name
Virtual Bus Driver (VBD)
BCM5708, BCM5709 32-bit bxvbdx.sys
BCM5708, BCM5709 64-bit bxvbda.sys
BCM57710, BCM57711,
BCM57712, BCM57840
32-bit evbdx.sys
BCM57710, BCM57711,
BCM57712, BCM57840
64-bit evbda.sys
Miniport Driver Broadcom Base Driver
Windows Server 2008 (NDIS 6.0) 32-bit bxnd60x.sys
Windows Server 2008 (NDIS 6.0) 64-bit bxnd60a.sys
Windows Server 2008 R2 (NDIS
6.0)
64-bit bxnd60a.sys
Windows Server 2012 64-bit bxnd60a.sys
Broadcom Advanced Server
Windows Server 2008 32-bit, 64-bit basp.sys