OK - this is solved now. You need to add the following to the port definition on the S4048T intf-type cr4 autoneg
Has anyone ever connected a S4148T (OS10) and S4048T (OS9) together via QSFP+ 40Gb? We can connect S4048Ts together all day long. We try connecting to S4148T and the port lights up for a few seconds and then the port shutdowns on the S4148T. Some background and Information: Using a Dell branded QSFP+ DAC cable. Running latest firmware on both switches OS Version: 10.5.3.0Build Version: 10.5.3.0.44 Dell EMC Application Software Version: 9.14(2.10) S4148T using port profile 2. Port configuration on S4048T: !interface fortyGigE 1/52no ip addressswitchportno shutdown Port configuration on S4148T: !interface ethernet1/1/27no shutdownswitchport access vlan 2flowcontrol receive offflowcontrol transmit off Any ideas welcome?
Connecting a S4148T and S4048T by 40Gb QSFP