ccna interview questions and answers

Part - 48 CCNA Interview Questions and Answers

270 Which of the following are Distant Vector protocols?

A.) IGRP

B.) RIP

C.) OSFP

D.) EIGRP

Ans A B

RIP and IGRP are Distance Vectoring protocols that send their entire routing tables to their neighbors. In some Cisco literature, EIGRP is listed as an 'advanced distance vector' routing protocol. However, the official curriculum courseware considers EIGRP a 'hybrid' protocol.

271 UDP works at which layer of the DOD model?

A.) Internet

B.) Host-to-Host

C.) Transport

D.) Data Link

Ans B

The TCP/IP Transport Layer (OSI) and Host to Host (DOD) protocols use TCP and UDP.

272 Of the following switching types, which one has the lowest latency?

A.) Cut-through

B.) Fragment Free

C.) None

D.) Store-and-forward

Ans A

Cut-Through switching copies only the destination address which is the first 6 bytes after the frame preamble into its buffer. The LAN switch then looks up the destination address in its switching table and determines the outgoing interface. The frame is then sent to the interface. A cut-through switch provides reduced latency because it begins to forward the frame as soon as it read the destination address and determines the outgoing interface.

273 What is an administrative distance of 0 mean?

A.) 0 means unbelievable

B.) 0 is for EIGRP

C.) 0 is the default distance for directly connected networks

D.) 0 means unreachable

Ans C

Directly connected network have the lowest administrative distance of 0. They are considered the most reliable.

274 Which of the following describe full-duplex transmission?

A.) Uses a single wire

B.) Data transmission in only both directions, but only one way at a time

C.) Uses a point-to-point connection from the transmitter of the transmitting station to the receiver of the receiving station

D.) Data transmission in only one direction

Ans C

Full Duplex - Capability for simultaneous data transmission between a sending station and a receiving station. It requires a workstation be attached to a switch, the NIC must support it, and collision detection and loopback must be disabled.

275 Which of the following is a connectionless protocol at the Transport layer?

A.) UDP

B.) ARP

C.) ICMP

D.) RARP

E.) IP

F.) FTP

Ans A

User Datagram Protocol - UDP is a connectionless oriented transport protocol for use when the upper layers provide error-recovery and reliability. UDP does not sequence data or re-assemble it into any order after transmission. This protocol uses Port 17.

276 What is the routing metric used by IGRP?

A.) MTU, delay, bandwidth, reliability, and loading

B.) Count to infinity

C.) TTL

D.) Hop count

Ans A

IGRP is a distance vector routing protocol designed by Cisco. The maximum hop count is 255, and it uses a combination of variables to determine a composite metric. IGRP has an administrative distance of 100.

277 What does 'P' mean when running a Trace?

A.) Good route

B.) Protocol unreachable

C.) Source Quench

D.) Destination unreachable

Ans B

When a P is returned when a Trace is run, it means the Protocol is unreachable.

278 What is the Network Layer of the OSI responsible for?

A.) Bridging

B.) Routing packets through an internetwork

C.) Regenerating the digital signal

D.) Gateway services

Ans B

The Network Layer routes data from one node to another, sends data from the source network to the destination network. The router will use packet switching to move a packet from one interface or port, to another through the network cloud.

279 Which layer is responsible for routing through an internetwork?

A.) Physical

B.) Session

C.) Network

D.) Transport

E.) Application

F.) Data Link

Ans C

The Network layer is responsible for routing. This is the primary job of routers, which operate at the Network layer.

280 What three occurrences will reset the holddown timer after a triggered update?

A.) Infinity is finally defined as some max number

B.) HD Timer expires

C.) Another update is received indicating a better metric

D.) The router receives a processing task proportional to the number of links in the internetwork

E.) The router detects fault LSP's propagating through the internetwork

F.) Another update is received indicating net status changed

Ans B D F

The HD Timer expires, another update is received indicating net status change, or if the router receives a processing task proportional to the number of links in the internetwork, this reset the holddown timer. These are all triggered updates.