Cisco Nexus 7000 Design Manual page 34

FlexPod Implementation and Design
Port-aggregation is supported by the second-generation Cisco UCS 6200 Series Fabric Interconnects,
2200 Series Fabric Extenders and 1200 Series Virtual Interface Cards (VIC) support port aggregation.
This capability allows for workload rebalancing between these devices providing link fault tolerance in
addition to increased aggregate bandwidth within the fabric. It should be noted that in the presence of
second generation VICs and FEX fabric port channels will automatically be created in the fabric. Fabric
port channels between the FEXs and fabric interconnects are controlled through the Chassis/FEX
discovery policy. Figure 12 shows the two modes of operation for this policy. In Discrete Mode, each
FEX KR connection and server connection is tied or pinned to a network fabric connection homed to a
port on the fabric interconnect. In the presence of a failure on the external "link" all KR connections are
disabled within the FEX I/O module. In the case of a fabric port channel discovery policy, the failure of
a network fabric link allows for redistribution of flows across the remaining port channel members. This
is less disruptive to the fabric.
Figure 12 Example of Discrete Mode versus Port Channel Mode Example
First generation Cisco UCS hardware is compatible with the second-generation gear but it will only
Note
operate in discrete mode.
Figure 13 shows one of the Cisco UCS B200-M3 backplane connections validated for the FlexPod. The
Cisco UCS B200M3 server uses a VIC 1240 in the mLOM slot with an empty mezzanine slot. The Cisco
UCS Fabric Extender 2204XP enables 2 KR lanes to the half-width blade while the global discovery
policy dictates the formation of a fabric port channel. Figure 10 details on particular instance of this
configuration. Notice that the instantiation of fabric port channels Po1027 and Po1155 between the
fabric interconnect and FEX pairs due to the discovery policy, and the automatic port channels formed
between Po1282 and Po1283 at the adapter and FEX level.
VMware vSphere 5.1 on FlexPod with Nexus 7000 Using FCoE
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