Actually this is a possible the explanation:
Once you have assigned the switch number just exit, DO NOT ASSIGN SWITCH PRIORITY YET! If you assign switch priority after assigning the number you will encounter virtual switch link configuration problem...
I have a really similar setup...but it's not easy to find documentation.Is it necessary an additional module? By the way, 3.5.x is fine From the Release notes:MACSec Encryption on Cisco Catalyst 4500-X- IEEE 802.1ae MACSec Layer 2 encryption- IEEE 80...
