Hi @BBeardPHC,

It depends on the end device that the port connecting to, what cable are you using and what is the end device's port information? Port 49, 50, 51, 52 are QSFP28-DD.

https://dell.to/3vqhz21

I want to connect a firewall to the switch using port 49 (or 50 which seems to be the same) using a QSFP+ 40GBASE-SR4.  Do I configure port 49 and disable 50?  Do I just configure both 49 and 50?  How does having 2 interfaces on a physical port work if you're not breaking it out into 2 interfaces?

BBeardPHC,

To answer the question as to why they have the same serial number, it is due to 49 and 50 being in the same port group, as seen here.

Now in regards to your other questions, I think your configuration will work but port 50 won't be useable unless you use a breakout cable, based on page 93 here

Let me know if this helps.

I get a 404 when I follow that link.  

Does the one here work for you?

Let me know.