The IP header contains a protocol field. If this field contains the value of 1, what type of data is contained within
the IP datagram?

A.
TCP.

B.
ICMP.

C.
UDP.

D.
IGMP.

Explanation:
The IP header protocol field value for ICMP is 1.
Incorrect Answers:
A: The IP header protocol field value for TCP is 6, not 1.
C: IP header protocol field value for UDP is 17, not 1.
D: The IP header protocol field value for IGMP is 2, not 1.
Stewart, James M., Ed Tittel, and Mike Chapple, CISSP: Certified Information Systems Security Professional
Study Guide, 5th Edition, Sybex, Indianapolis, 2011, p. 122