Cisco Exam Questions

what is the default encapsulation?

When configuring a serial interface on a router, what is the default encapsulation?

A.
atm-dxi

B.
frame-relay

C.
hdlc

D.
lapb

E.
ppp

Explanation:
This question is to examine the data link layer protocols.
LAPB. Link Access Procedure Balanced for x.25
PPP: Point-to-Point Protocol
HDLC. High-Level Data Link Control
Frame-relay and the three protocols above are data link layer protocols. HDLC is the default serial
encapsulation protocol.
The correct answer is C.