Greetings.
See https://www.cisco.com/c/en/us/products/collateral/switches/nexus-5000-series-switches/datasheet-c78-730760.html
Cisco Nexus 56128P Switch
The Cisco Nexus 56128P Switch (Figure 5) is a 2RU switch that supports 2.56 Tbps of bandwidth across 48 fixed 1 and 10 Gigabit Ethernet SFP+ ports and four 40-Gbps QSFP+ ports. The 48 ports on the base chassis support 10 Gigabit Ethernet and FCoE. The 4 QSFP ports support 40 Gigabit Ethernet and FCoE.
The Cisco Nexus 56128P also offers two slots for a Generic Expansion Module (GEM). The GEM (Figure 6) for the Cisco Nexus 56128P provides 24 SFP+ ports for 10 Gigabit Ethernet and FCoE or 2-, 4-, and 8-Gbps Fibre Channel, and 2 QSFP+ ports for 40 Gigabit Ethernet and FCoE. The expansion module supports native 40 Gigabit Ethernet on the QSFP+ ports. The GEM is supported on the Cisco Nexus 56128P chassis only and can be populated in either of the two expansion slots.
You need a GEM module for native FC.
Thanks,
Kirk...
