CCNA LAB (QUESTION AND ANWSER)
Question No : 1 - Topic 1
Where does routing occur within the DoD TCP/IP reference model?
- A. application
- B. internet
- C. network
- D. transport
Answer : B
Explanation: The picture below shows the comparison between TCP/IP model & OSI model. Notice that the Internet Layer of TCP/IP is equivalent to the Network Layer which is responsible for routing decision.
Question No : 2 - Topic 1
Which of the following statements describe the network shown in the graphic? (Choose
two.)
two.)
- A. There are two broadcast domains in the network.
- B. There are four broadcast domains in the network.
- C. There are six broadcast domains in the network.
- D. There are four collision domains in the network.
- E. There are five collision domains in the network.
- F. There are seven collision domains in the network.
Answer : A,F
Explanation: Only router can break up broadcast domains so in the exhibit there are 2 broadcast domains: from e0 interface to the left is a broadcast domain and from e1 interface to the right is another broadcast domain ->. Both router and switch can break up collision domains so there is only 1 collision domain on the left of the router (because hub doesnt break up collision domain) and there are 6 collision domains on the right of the router (1 collision domain from e1 interface to the switch + 5 collision domains for 5 PCs in Production)
Question No : 3 - Topic 1
A network interface port has collision detection and carrier sensing enabled on a shared
twisted pair network. From this statement, what is known about the network interface port?
twisted pair network. From this statement, what is known about the network interface port?
- A. This is a 10 Mb/s switch port.
- B. This is a 100 Mb/s switch port.
- C. This is an Ethernet port operating at half duplex.
- D. This is an Ethernet port operating at full duplex.
- E. This is a port on a network interface card in a PC.
Answer : C
Explanation: Modern Ethernet networks built with switches and full-duplex connections no longer utilize CSMA/CD. CSMA/CD is only used in obsolete shared media Ethernet (which uses repeater or hub).
Question No : 4 - Topic 1
Host 1 is trying to communicate with Host 2. The e0 interface on Router C is down.
Which of the following are true? (Choose two.)
- A. Router C will use ICMP to inform Host 1 that Host 2 cannot be reached.
- B. Router C will use ICMP to inform Router B that Host 2 cannot be reached.
- C. Router C will use ICMP to inform Host 1, Router A, and Router B that Host 2 cannot be reached.
- D. Router C will send a Destination Unreachable message type.
- E. Router C will send a Router Selection message type.
- F. Router C will send a Source Quench message type.
Answer : A,D
Explanation: Host 1 is trying to communicate with Host 2. The e0 interface on Router C is down. Router C will send ICMP packets to inform Host 1 that Host 2 cannot be reached.
Question No : 5 - Topic 1
Refer to the exhibit.
Based on the information given, which switch will be elected root bridge and why?
- A. Switch A, because it has the lowest MAC address
- B. Switch A, because it is the most centrally located switch
- C. Switch B, because it has the highest MAC address
- D. Switch C, because it is the most centrally located switch
- E. Switch C, because it has the lowest priority
- F. Switch D, because it has the highest priority
Answer : E
Explanation: To elect the root bridge in the LAN, first check the priority value. The switch having the lowest priority will win the election process. If Priority Value is the same then it checks the MAC Address; the switch having the lowest MAC Address will become the root bridge. In this case, switch C has the lowest MAC Address so it becomes the root bridge.
Question No : 6 - Topic 1
Which layer in the OSI reference model is responsible for determining the availability of the
receiving program and checking to see if enough resources exist for that communication?
receiving program and checking to see if enough resources exist for that communication?
- A. transport
- B. network
- C. presentation
- D. session
- E. application
Answer : E
Explanation: This question is to examine the OSI reference model. The Application layer is responsible for identifying and establishing the availability of the intended communication partner and determining whether sufficient resources for the intended communication exist.
Question No : 7 - Topic 1
Refer to the graphic.
Host A is communicating with the server. What will be the source MAC address of the
frames received by Host A from the server?
- A. the MAC address of router interface e0
- B. the MAC address of router interface e1
- C. the MAC address of the server network interface
- D. the MAC address of host A
Answer : A
Explanation: Whereas switches can only examine and forward packets based on the contents of the MAC header, routers can look further into the packet to discover the network for which a packet is destined. Routers make forwarding decisions based on the packet's network- layer header (such as an IPX header or IP header). These network-layer headers contain source and destination network addresses. Local devices address packets to the router's MAC address in the MAC header. After receiving the packets, the router must perform the following steps: 1. Check the incoming packet for corruption, and remove the MAC header. The router checks the packet for MAC-layer errors. The router then strips off the MAC header and examines the network-layer header to determine what to do with the packet. 2. Examine the age of the packet. The router must ensure that the packet has not come too far to be forwarded. For example, IPX headers contain a hop count. By default, 15 hops is the maximum number of hops (or routers) that a packet can cross. If a packet has a hop count of 15, the router discards the packet. IP headers contain a Time to Live (TTL) value. Unlike the IPX hop count, which increments as the packet is forwarded through each router, the IP TTL value decrements as the IP packet is forwarded through each router. If an IP packet has a TTL value of 1, the router discards the packet. A router cannot decrement the TTL value to 1 and then forward the packet. 3. Determine the route to the destination. Routers maintain a routing table that lists available networks, the direction to the desired network (the outgoing interface number), and the distance to those networks. After determining which direction to forward the packet, the router must build a new header. (If you want to read the IP routing tables on a Windows 95/98 workstation, type ROUTE PRINT in the DOS box.) 4. Build the new MAC header and forward the packet. Finally, the router builds a new MAC header for the packet.
Question No : 8 - Topic 1
A router has two Fast Ethernet interfaces and needs to connect to four VLANs in the local
network. How can you accomplish this task, using the fewest physical interfaces and
without decreasing network performance?
network. How can you accomplish this task, using the fewest physical interfaces and
without decreasing network performance?
- A. Use a hub to connect the four VLANS with a Fast Ethernet interface on the router.
- B. Add a second router to handle the VLAN traffic.
- C. Add two more Fast Ethernet interfaces.
- D. Implement a router-on-a-stick configuration.
Answer : D
Explanation: A router on a stick allows you to use sub-interfaces to create multiple logical networks on a single physical interface.
Question No : 9 - Topic 1
Match the terms on the left with the appropriate OSI layer on the right. (Not all options are
used.)
used.)
Answer :
Question No : 10 - Topic 1
establishing an FTP connection to a remote server. What is the highest layer of the
protocol stack that the network administrator is using for this operation?
Question No : 11 - Topic 1
(Choose two.)