ccna interview questions and answers

Part - 52 CCNA Interview Questions and Answers

326 What is the IEEE specification for Spanning Tree Protocol?

A.) 802.9

B.) 803.ud

C.) 803

D.) 802.1d

Ans D

IEEE 8021.d Spanning Tree Protocol (STP) was developed to prevent routing loops in a network. If a router, switch, or hub has more then one path to the same destination, a routing problem could occur. To prevent this, the Spanning Tree Protocol is executed between the devices to detect and logically block redundant paths from the network. The main function of the Spanning Tree Protocol is to allow redundant network paths without suffering the effects of loops in the network. The Spanning Tree Algorithm (STA) implemented by STP prevents loops by calculating a stable Spanning Tree network topology. When creating fault tolerant internetworks, a loop-free path must exist between all Ethernet nodes in the network. Spanning Tree frames called Bridge Protocol Data Units (BPDUs) are sent and received by all switches in the network at regular intervals.

327 CO is an acronym for which of the following?

A.) Central Office

B.) Capital Office

C.) Central Operator

D.) Company Office

Ans A

Central Office (CO) - A switching facility that provides the nearest point of presence for a provider's WAN service.

328 What is convergence time?

A.) The update time

B.) The time it takes to reload a router

C.) The time it takes for a packet to reach its destination

D.) The time is takes for all routers update their tables after a change takes place

Ans D

Convergence is slower for Distant Vector routing and is faster for Link State routing.

329 Which of the following are Session Layer standards?

A.) ASCII and EBCDIC

B.) MPEG and MIDI

C.) NFS and SQL

D.) JPEG and PICT

Ans C

Session layer protocols include NFS, SQL, RPC, Appletalk Session Protocol (ASP), XWindows, and NetBEUI.

330 What is the IP extended access list range?

A.) 1000-1099

B.) 100-199

C.) 1-99

D.) 101-200

Ans B

100-199 is the range for Extended IP access lists.

331 Define Poison Reverse?

A.) To prevent regular update messages from reinstating a route that has gone down

B.) Packets sent out that are not destined for a network go to the default network

C.) Information received on an interface cannot be sent back out the same interface

D.) When a network goes down, the router enters in its table the number 16 to signify destination unreachable

Ans D

By entering a 16 as the hop count, the other routers know that the destination is unreachable.

332 What is the default interval for SAP updates?

A.) 60 seconds

B.) 15 seconds

C.) 30 seconds

D.) 120 seconds

Ans A

By default, the SAP (Service Access Protocol) sends out updates every 60 seconds. This value can be changed to alter the update interval. To decrease WAN traffic, the update interval could be increased to every 5 minutes.

333What does a router do with a packet that it does not have a destination network for?

A.) Sends it to the Serial port

B.) Drops the packet

C.) Sends it back out the same interface it received it in

D.) Forwards the packet to the next hop Ans B When a router does not have a destination for a packet, it drops the packet into the bit bucket.

334 What type of frame does CDP use to gather information about it's neighbors?

A.) TCP/IP

B.) Novell-ether

C.) Subnetwork Access Protocol (SNAP)

D.) Ethernet_II Ans C Cisco Discovery Protocol is a proprietary protocol to allow you to access configuration information on other routers and switches with a single command. It uses SNAP at the Data-Link Layer. By default CDP sends out a broadcast every 60 seconds and it holds this information for 180 seconds. CDP is enabled by default.

335 Which protocol is used for booting diskless workstations?

A.) IP

B.) ARP

C.) RARP

D.) TCP

E.) SNMP

Ans C Reverse Address Resolution Protocol - RARP is ARP's counterpart, but it resolves IP addresses to MAC addresses typically on diskless workstations.

336 Which layer is responsible for synchronizing sending and receiving applications?

A.) Presentation

B.) Session

C.) Transport

D.) Application

E.) Network

Ans D

The Application layer performs the following: Synchronizing sending and receiving applications. Program-to program communication. Identify and establish the availability of the intended communication partner, and determine if sufficient resources exist for the communication.
Popular application protocols include WWW, SMTP, EDI, FTP, Telnet, and SNMP

337 Which protocol gets a hardware address from a known IP address?

A.) RARP

B.) TCP

C.) IP

D.) BootP

E.) ARP

F.) ICMP

Ans E

Address Resolution Protocol - ARP is responsible for resolving MAC addresses to IP address. It stores these in its arp cache for later use. It does this to inform a lower layer of the destination's MAC address.

338 Which layer defines bit synchronization?

A.) Application

B.) Network

C.) Transport

D.) Physical

E.) Session

F.) Session

Ans D

The Physical layers deals with synchronizing the 1s and 0s on the wire.

339 Which is true regarding half duplex Ethernet operation?

A.) Half Duplex ethernet technology provides a transmit circuit connection wired directly to the receiver circuit at the other end

B.) Half duplex transmission between stations is achieved by using point to multipoint Ethernet and Fast Ethernet

C.) With Half Duplex transmission logically circuits feed into a single cable creating a situation similar to a one way bridge

D.) Half Duplex transmission between stations is achieved using Point to Point Ethernet & Fast Ethernet Ans C Half-Duplex - Capability for data transmission in only one direction at a time between sending station and a receiving station.

340 When would you use ISDN?

A.) To connect LANs using POTS

B.) To support applications requiring voice, data, and video

C.) When you need a consistent and very high rate of data speed

D.) To connect to IBM mainframes Ans B IDSN supports high speed voice, data and video and is a good choice for many small businesses.

350 Which protocol will send a message to routers if a network outage or congestion occurs?

A.) ARP

B.) TCP

C.) IP

D.) ICMP

Ans D

Internet Control Message Protocol - ICMP is a management protocol and messaging service provider for IP. Its messages are carried as IP datagrams. ICMP is used in the following events: Destination Unreachable - If a router cannot send an IP packet any further, it uses an ICMP echo to send a message back to the sender notifying it that the remote node is unreachable. Buffer Full - If a routers memory buffer is full ICMP will send out a message to the originator. Hops - Each IP datagram is assigned a path. This consists of hops. If it goes through the maximum number of hops, the packet is discarded and the discarding router sends an ICMP echo to the host. Ping - Ping use ICMP echo message to check connectivity.