A technician is troubleshooting connectivity problems between two routers that are directly
connected through a serial line. The technician notices that the serial line is up, but cannot see any
neighbors displayed in the output of the show cdp neighbors command.
In which OSI layer is the problem most likely occurring?
A.
physical
B.
data link
C.
network
D.
transport
E.
application
Explanation:
CDP operates at layer 2 of the OSI model.