A Cisco router that was providing Frame Relay connectivity at a remote site was replaced with a
different vendor’s frame relay router. Connectivity is now down between the central and remote
site. What is the most likely cause of the problem?
A.
incorrect IP address mapping
B.
incorrect DLCI
C.
mismatched encapsulation types
D.
mismatched LMI types
Explanation:
LMI does have to be the same on both “ends”, but when you’re talking about LMI, one end is your
local router and the other end is the carrier’s frame relay switch. The two routers can use different
LMI types as long as the ports on the frame relay switch use the correct LMI type. Encapsulation
also has to be the same between both ends, but now we’re talking about the “ends” being the two
routers. Cisco defaults to a proprietary frame relay encapsulation. To interoperate with other
vendors, you must use “encapsulation frame-relay ietf”. This is a common problem in a multivendor environment.