Changing the QSFP Port Speed

Using the set port speed Command

When using the set port speed command to change the QSFP port speed, all ports in the port speed group are configured for the new port speed mode. This command only affects ports that have an operational status of present (any status not not-pres). If the show port status command displays the operational status as not-pres, using this command will have no affect.

To change the operational speed for the QSFP ports in the port speed group with fg.4.1 in the present state from 40Gbps to 10Gbps, first verify that ports fg.1.1-2 are in a present state using the show port status command:

System(su)->show port status *.4.1-2
Port         Alias            Oper     Admin   Speed  Duplex  Type
             (truncated)      Status   Status  (bps)
------------ ---------------- -------- ------- ------ ------- ------------------
tg.4.1                        not-pres up                     unknown
tg.4.2                        not-pres up                     unknown
tg.4.3                        not-pres up                     unknown
tg.4.4                        not-pres up                     unknown
tg.4.5                        not-pres up                     unknown
tg.4.6                        not-pres up                     unknown
tg.4.7                        not-pres up                     unknown
tg.4.8                        not-pres up                     unknown
com.4.1                       down     up        9.6K         rs232        usb
fg.4.1                        down     up       40.0G full    unknown
fg.4.2                        down     up       40.0G full    unknown
11 of 11 ports displayed, 0 port(s) with oper status 'up' or 'dormant'.
System(su)->

The output shows that the 10Gbps members of the port speed group are not present and that the 40Gpbs members are present and in an operational status down state. The port speed is changed for both members of the port speed group by specifying either port or both ports in the command entry. To change the speed to 10Gbps for the port speed group containing ports fg.4.1-2 enter either port or both along with the new speed, enter:

System(su)->set port speed fg.4.1 10000
System(su)->

You must reset the module for the new speed to take affect only after the reset. Use the show port status command again to confirm the speed change. Ports fg.4.1-2 will now display as not-pres and ports tg.4.1-8 will have a present status of either up or down.

To change the operational speed for the QSFP ports in the port speed group with tg.4.1 in the present state from 10Gbps to 40Gbps, enter:

System(su)->set port speed tg.4.1 40000
System(su)->

The operational status for ports tg.4.1-8 will be set to not-pres and the operational status for ports fg.4.1-2 will be set to present (up or down) upon resetting the module.

Inserting a Single Speed QSFP

The port speed of a speed group member can be changed by inserting a QSFP that supports a single operating speed that does not conflict with the operating speed of the other member of the port speed group. A conflict is defined as a QSFP in the port for the speed you wish to change requiring a different speed than is currently operating and there is a QSFP installed in the other member of the port speed group that is compatible with the current operating speed you wish to change. If there is conflict Syslog reports the conflict.

Port Speed Change Prior to Reset

After a speed change has been set, but prior to the reset for the module containing the port:

• The system reports a Syslog message indicating the module containing the port must be reset for the new speed change to take affect
• All ports, in the port speed group associated with the new operating speed, remain in the not-pres state until module resets
• The ports, in the port speed group not associated with the new desired operating speed, go into an oper-status down state with oper-status cause specified as self (system initiated)

Use the show port operstatus command to display the current port oper-status cause.

The module containing the modified ports must be reset to complete the speed transition.

Retracting a Requested Speed Change

To retract a requested speed change, insert or remove and reinsert a QSFP in the port speed group that can operate in the original speed. Upon inserting or reinserting the QSFP:

• Ports will no longer be held in the oper-status down state with the self cause and will return to normal operation immediately
• The speed change scheduled for the next reset is canceled
• The show port commands revert to the status prior to the speed change request