I have a Cisco Nexus 5596 with 48 Ethernet Ports (two of which are now configured for Fibre Channel). It has a FEX attached to it as well.
I was able to configure ANY Ethernet port with the typical interface commands when in interface configuration mode. However, I can now only configure existing and new Port Channel interfaces, FEX ports and standard Ethernet ports that have never been configured before.
If I try to configure an Ethernet interface that was configured in the past, I only seem to have access to global interface commands when in interface configuration mode. I can set spanning-tree, duplex, speed or any other interface parameters. The CLI acts like I'm not in interface config mode, but the prompt shows that I am.
Anyone else seen such a thing? I am logged in as admin.