Which of the following is an authentication service that uses UDP as a transport medium?
A.
TACACS+
B.
LDAP
C.
Kerberos
D.
RADIUS
Explanation:
RADIUS runs in the application layer and makes use of UDP as transport.
Incorrect Answers:
A: TACACS+ makes use of TCP.
B: LDAP makes use of TCP.
C: Kerberos Makes use of both UDP and TCP.http://en.wikipedia.org/wiki/RADIUS
http://en.wikipedia.org/wiki/TACACS
Stewart, James Michael, CompTIA Security+ Review Guide, Sybex, Indianapolis, 2014, p 273.
https://tools.ietf.org/html/rfc6251