Cisco CCNA mock exam questions sample test – Question 420

.Which of the following protocols is responsible for negotiating upper-layer protocols that will be carried across a Point-to-Point Protocol (PPP) connection?

A. LCP
B. NCP
C. LMI
D. ISDN

Correct Answer: B

Explanation:
Network Control Protocol (NCP) is responsible for negotiating upper-layer protocols that will be carried across the PPP connection. NCP defines how the two PPP peers negotiate with
the network layer protocols, such as IP and IPX, which will be used across the PPP connection.
Link Control protocol (LCP) is not responsible for negotiating upper-layer protocols that will be carried across a PPP connection. Link Control protocol (LCP) has the primary
responsibility of negotiating and maintaining the PPP connection. LCP, defined in Request for Comments (RFCs) 1548 and 1570, has the primary responsibility to establish, configure,
authenticate, and test a PPP connection. LCP negotiates the following when setting up a PPP connection:
Authentication method used (PAP or CHAP), if any
Compression algorithm used (Stacker or Predictor), if any
Callback phone number to use, if defined
Multilink; other physical connections to use, if configured
Local Management Interface (LMI) is not responsible for negotiating upper-layer protocols that will be carried across the PPP connection. LMI is a characteristic of a frame relay
connection. There are three types of LMIs supported by Cisco routers:
Cisco
ANSI Annex D
Q933-A Annex A
LMI has nothing to do with PPP connections.
Integrated Services Digital Network (ISDN) is a type of WAN connection and has nothing to do with PPP connections.
Objective:
WAN Technologies
Sub-Objective:
Configure and verify PPP and MLPPP on WAN interfaces using local authentication
References:
Cisco > Internetworking Technology Handbook > Point-to-Point Protocol
Cisco > Support > Technology Support > WAN > Point-to-Point Protocol (PPP) > Design > Design Technotes > Understanding and Configuring PPP CHAP Authentication >
Document ID: 25647
CCNA ICND2 Official Exam Certification Guide (Cisco Press, ISBN 1-58720-181-X), Chapter 12: Point-to-Point WANs, pp. 436-441.