A customer reports that they are missing vPC peer link redundancy between two Cisco Nexus 5548UP switches. The interfaces on both switches are configured and cabled correctly. The interface status is up/down on switch 1 and up/up on switch 2.
Which two steps should be taken to isolate the root cause? (Choose two.)
A. determine whether the fiber-optic cable manufacturer is valid under the interoperability matrix
B. swap the ends of the fiber-optic cable
C. swap the transceivers between the two interfaces
D. determine whether the fiber-optic cable type (single mode or multimode) matches the X2 modules
E. ask the customer if the link was ever functional
