Users Guide

QSFP28-DD Ethernet interfaces support Fabric Expander mode (FEM) and native Ethernet mode.
● In FEM mode, an 8x25GE interface connects only to an attached Fabric Expander using supported cables.
● In native Ethernet mode, an interface connects to an upstream switch, rack server, or other Ethernet device.
By default, QSFP28-DD port groups 1 to 9 are configured in FEM mode with 8x25GE breakout interfaces enabled. QSFP28-DD
port groups 10 to 12 are configured in native mode with 2x100GE breakout interfaces enabled.
● For information about how to configure single-density QSFP28 Ethernet port groups 13 and 14, see Single-density QSFP28
interfaces.
● For information about how to configure unified port groups 15 and 16 to operate in Ethernet or Fibre Channel mode, see
Unified port groups on page 247.
● If an MX9116n module is in SmartFabric mode, use the OpenManage Enterprise - Modular interface to configure breakout
interfaces and speed on a QSFP28-DD port.
1. To configure a QSFP28-DD port interface, enter PORT-GROUP mode from CONFIGURATION mode. Enter 1/1 for node/
slot. The QSFP28-DD port-group range is 1 to 12.
port-group node/slot/port-group
2. (Optional) To verify the current QSFP28-DD port-group configuration, enter the show port-group command.
OS10# show port-group
Port-group Mode Ports FEM
port-group1/1/1 Eth 25g-8x 17 18 FEM
port-group1/1/2 Eth 25g-8x 19 20 FEM
port-group1/1/3 Eth 25g-8x 21 22 FEM
port-group1/1/4 Eth 25g-8x 23 24 FEM
port-group1/1/5 Eth 25g-8x 25 26 FEM
port-group1/1/6 Eth 25g-8x 27 28 FEM
port-group1/1/7 Eth 25g-8x 29 30 FEM
port-group1/1/8 Eth 25g-8x 31 32 FEM
port-group1/1/9 Eth 25g-8x 33 34 FEM
port-group1/1/10 Eth 100g-2x 35 36 -
port-group1/1/11 Eth 100g-2x 37 38 -
port-group1/1/12 Eth 100g-2x 39 40 -
...
To reset a QSFP28-DD port group to its default setting, enter the no mode command in PORT-GROUP mode. This
command sets QSFP-DD port groups 1 to 9 to 8x25GE FEM mode and QSFP-DD port groups 10 to 12 to 2x100GE mode.
no mode
3. To activate a QSFP28-DD interface for Ethernet operation, enter the mode Eth command in PORT-GROUP mode.
mode Eth {100g-2x | 50g-4x | 40g-2x | 25g-8x fabric-expander-mode | 25g-8x | 10g-8x}
● 100g-2x — Split a QSFP28-DD port into two 100GE interfaces.
● 50g-4x — Split a QSFP28-DD port into four 50GE interfaces.
● 40g-2x — Split a QSFP28-DD port into two 40GE interfaces.
● 25g-8x fabric-expander-mode — Split a QSFP28-DD port into eight 25GE interfaces for connection only to an
MX7116n Fabric Expander.
● 25g-8x — Split a QSFP28-DD port into eight 25GE interfaces.
● 10g-8x — Split a QSFP28-DD port into eight 10GE interfaces.
4. Return to CONFIGURATION mode.
exit
5. Enter Ethernet Interface mode to configure other settings. Enter a single interface, a hyphen-separated range, or multiple
interfaces separated by commas.
interface ethernet node/slot/port[:subport]
To display the Ethernet 100GE port configuration in a QSFP28-DD port group, enter the show port-group command. To
display the Ethernet 25GE subport configuration, enter the show interfaces status command.
PowerEdge MX Ethernet I/O modules
317