Which of the following protocols does not operate at the data link layer (layer 2)?

A.
PPP

B.
RARP

C.
L2F

D.
ICMP

Explanation:
ICMP works at the network layer of the OSI model.
Incorrect Answers:
A: RARP is a data link layer protocol.
B: L2F is a data link layer protocol.
C: ICMP is a data link layer protocol.

https://en.wikipedia.org/wiki/Network_layer