Port Speed and Duplex Mode Configuration

The following example sets the port speed of copper interface 8 on a FastIron device to 100-Mbps, operating in full-duplex mode. 

device(config)# interface ethernet 1/1/8
device(config-if-e1000-1/1/8)# speed-duplex 100-full
For ICX 7850-48F, SFP28 devices, ports are grouped into fours. For example, ports 1/1/1 to 1/1/4 are one group and ports 1/1/5 to 1/1/8 are another group, and so on. All ports in a four-port group must be configured to the same value. This restriction does not apply if configuring values between 1-Gbps and 10-Gbps.

The following example shows how to change the port speed for an entire four-port group to 10-Gbps.

ICX7850-48F# configure terminal                                     
ICX7850-48F(config)# interface ethernet 1/1/21 to 1/1/24
ICX7850-48F(config-mif-1/1/21-1/1/24)# speed-duplex 10g-full
ICX7850-48F(config-mif-1/1/21-1/1/24)# end
The following example demonstrates how to change the port speed when using a mix of 1-Gbps and 10-Gbps in the same four-port group. Consider ports 1/1/17, 1/1/18, and 1/1/20 operating at 10-Gbps speed, while port 1/1/19 is operating at 1-Gbps speed. You would need to configure the speed-duplex command to 1000-full for the group, and then apply the speed-duplex command to 10g-full for the ports intended to operate at 10-Gbps speed.

ICX-7850-48F# configure terminal
ICX-7850-48F(config)# interface ethernet 1/1/17 to 1/1/20
ICX-7850-48F(config-mif-1/1/17-1/1/20)# speed-duplex 1000-full
ICX7850-48F(config-mif-1/1/17-1/1/20)# interface ethernet 1/1/17 
ICX7850-48F(config-if-e25000-1/1/17)# speed-duplex 10g-full
ICX7850-48F(config-if-e25000-1/1/17)# interface ethernet 1/1/18
ICX7850-48F(config-if-e25000-1/1/18)# speed-duplex 10g-full
ICX7850-48F(config-if-e25000-1/1/18)# interface ethernet 1/1/20         
ICX7850-48F(config-if-e25000-1/1/20)# speed-duplex 10g-full
ICX7850-48F(config-if-e25000-1/1/20)# end

To confirm the port speed for each Ethernet interface, enter the show running interface ethernet command.

ICX7850-48F# show running interface ethernet 1/1/17
interface ethernet 1/1/17
speed-duplex 10g-full
!
ICX7850-48F# show running interface ethernet 1/1/18
interface ethernet 1/1/18
speed-duplex 10g-full
!
ICX7850-48F# show running interface ethernet 1/1/19
interface ethernet 1/1/19
speed-duplex 1000-full
!
ICX7850-48F# show running interface ethernet 1/1/20
interface ethernet 1/1/20
speed-duplex 10g-full
!

If you attempt to set the port speed to 10-Gbps without first entering the speed-duplex 1000-full command in case of mix of 1-Gbps and 10-Gbps in same four-port group, an error message will be displayed.

ICX-7850-48F# configure terminal
ICX-7850-48F(config)# interface ethernet 1/1/17 to 1/1/20
ICX7850-48F(config-mif-1/1/17-1/1/20)# speed-duplex 10g-full

ERROR: 1/1/19: optics <-> speed mismatch. Replace with SFP+ to enable link.
This speed is not allowed on port 1/1/17 due to quad portgroup speed restriction(portgroup: 1/1/17 to 1/1/20)
ERROR: 1/1/19: optics <-> speed mismatch. Replace with SFP+ to enable link.
This speed is not allowed on port 1/1/18 due to quad portgroup speed restriction(portgroup: 1/1/17 to 1/1/20)
ERROR: 1/1/19: optics <-> speed mismatch. Replace with SFP+ to enable link.
This speed is not allowed on port 1/1/19 due to quad portgroup speed restriction(portgroup: 1/1/17 to 1/1/20)
ERROR: 1/1/19: optics <-> speed mismatch. Replace with SFP+ to enable link.
This speed is not allowed on port 1/1/20 due to quad portgroup speed restriction(portgroup: 1/1/17 to 1/1/20)

Parent topic: Port speed and duplex mode modification