Hello!

Has anyone experienced bad-ports from the factory?

I have one port on one of two freshly-out-of-the-boxes CRS310-8G+2S+ switches that absolutely won't maintain a link at 2.5G on ether5. That port seems happy-ish at 1G, but the same systems/NICs have no problem linking and being happy at 2.5G on the other ports.

Thanks!

Regards,
goodbye

What ROS are you running ?

Maybe it's best for you to connect your 2.5G device to ether5, enable auto negotiation if you disabled it and create supout.rif file and send it to support so they can see what is the problem.