This document describes a problem that occurs when a Nexus 2248PQ Fabric Extender (FEX) is connected to a Nexus 7000 series switch which only has 40GB F3 modules installed.
Cisco recommends that you have knowledge of these topics:
Cisco Nexus 2000 Series configuration
Cisco Nexus 7000 Series configuration
The information in this document is based on these software and hardware versions:
Cisco Nexus 7009
Cisco Nexus 2248PQ
The information in this document was created from the devices in a specific lab environment. All of the devices used in this document started with a cleared (default) configuration. If your network is live, make sure that you understand the potential impact of any command.
The 2248PQ uplink ports are in the form of four Quad (4-channel) Small Form-factor Pluggable (QSFP) ports. However, these ports do not run natively at 40GB; the only supported configuration is to run these ports in 4x10GB mode.
The 40GB ports on the F3 modules do not show as FEX-capable:
N7K1-Nexus7009# show module 9 Mod Ports Module-Type Model Status --- ----- ----------------------------------- ------------------ ---------- 9 12 10/40 Gbps Ethernet Module N7K-F312FQ-25 ok
N7K1-Nexus7009# sh int e9/1 capabilities | i FEX FEX Fabric: no
However, these ports can be used for FEX connections to the 2248PQ. First, the port must be logically broken out:
N7K1-Nexus7009(config)# interface breakout module 9 port 1 map 10g-4x
After the breakout, we then see that the broken out 10GB ports are FEX-capable:
N7K1-Nexus7009# show int e9/1/1 capabilities | i FEX
FEX Fabric: yes
You can then connect a 2248PQ to this port using a 40GB QSFP or TwinAx cable; and then configure the four broken out ports into a port-channel: