Cisco CCNA

Chapter 4


1 Refer to the exhibit. Host1 is in the process of setting up a TCP session with Host2. Host1 has sent a SYN message to begin session establishment. What happens next?

Host1 sends a segment with the ACK flag = 0, SYN flag = 0 to Host2.

Host1 sends a segment with the ACK flag = 1, SYN flag = 0 to Host2.

Host1 sends a segment with the ACK flag = 1, SYN flag = 1 to Host2.

Host2 sends a segment with the ACK flag = 0, SYN flag = 1 to Host1.

Host2 sends a segment with the ACK flag = 1, SYN flag = 0 to Host1.

*Host2 sends a segment with the ACK flag = 1, SYN flag = 1 to Host1.

2 Why is flow control used for TCP data transfer?

to synchronize equipment speed for sent data

to synchronize and order sequence numbers so data is sent in complete numerical order

*to prevent the receiver from being overwhelmed by incoming data

to synchronize window size on the server

to simplify data transfer to multiple hosts

3 Refer to the exhibit. What two pieces of information can be determined from the output that is shown? (Choose two.)

*The local host is using three client sessions.

*The local host is using web sessions to a remote server.

The local host is listening for TCP connections using public addresses.

The local host is using well-known port numbers to identify the source ports.

The local host is performing the three-way handshake with 192.168.1.101:1037.

4 Which event occurs during the transport layer three-way handshake?

The two applications exchange data.

*TCP initializes the sequence numbers for the sessions.

UDP establishes the maximum number of bytes to be sent.

The server acknowledges the bytes of data received from the client.

5 During a TCP communication session, if the packets arrive to the destination out of order, what will happen to the original message?

The packets will not be delivered.

The packets will be retransmitted from the source.

*The packets will be delivered and reassembled at the destination.

The packets will be delivered and not reassembled at the destination.

6 Which OSI model layer is responsible for regulating the flow of information from source to destination, reliably and accurately?

application

presentation

session

*transport

network

7 Which is an important characteristic of UDP?

acknowledgement of data delivery

*minimal delays in data delivery

high reliability of data delivery

same order data delivery

8 With TCP/IP data encapsulation, which range of port numbers identifies all well-known applications?

0 to 255

256 to 1022

*0 to 1023

1024 to 2047

49153 to 65535

9 What mechanism is used by TCP to provide flow control as segments travel from source to destination?

sequence numbers

session establishment

*window size

acknowledgments

10 Based on the transport layer header shown in the diagram, which of the following statements describe the established session? (Choose two.)

This is a UDP header.

*This contains a Telnet request.

This contains a TFTP data transfer.

The return packet from this remote host will have an Acknowledgement Number of 43693.

This is a TCP header.

11 Which transport layer protocol provides low overhead and would be used for applications which do not require reliable data delivery?

TCP

IP

*UDP

HTTP

DNS

12 Refer to the exhibit. In line 7 of this Wireshark capture, what TCP operation is being performed?

*session establishment

segment retransmit

data transfer

session disconnect

13 Which information is found in both the TCP and UDP header information?

sequencing

flow control

acknowledgments

*source and destination port

14 Why are port numbers included in the TCP header of a segment?

to indicate the correct router interface that should be used to forward a segment

to identify which switch ports should receive or forward the segment

to determine which Layer 3 protocol should be used to encapsulate the data

*to enable a receiving host to forward the data to the appropriate application

to allow the receiving host to assemble the packet in the proper order

15 Which two options represent Layer 4 addressing? (Choose two.)

identifies the destination network

identifies source and destination hosts

*identifies the communicating applications

*identifies multiple conversations between the hosts

identifies the devices communicating over the local media

16 Which three features allow TCP to reliably and accurately track the transmission of data from source to destination? (Choose three.)

*flow control

urgent pointer

best effort delivery

*session establishment

connectionless services

*numbering and sequencing

17 What is dynamically selected by the source host when forwarding data?

destination logical address

source physical address

default gateway address

*source port

18 After a web browser makes a request to a web server that is listening to the standard port, what will be the source port number in the TCP header of the response from the server?

13

53

*80

1024

1728

19 What are two features of the User Datagram Protocol (UDP)? (Choose two.)

flow control

*low overhead

*connectionless

connection-oriented

sequence and acknowledgements

20 Refer to the exhibit. Host A is using FTP to download a large file from Server 1. During the download process, Server 1 does not receive an acknowledgment from Host A for several bytes of transferred data. What action will Server 1 take as a result?

create a Layer 1 jam signal

*reach a timeout and resend the data that needs to be acknowledged

send a RESET bit to the host

change the window size in the Layer 4 header

Chapter 5

1. In an IPv4 environment, what information is used by the router to forward data packets from one interface of a router to another?
• destination network address

2. What information is added during encapsulation at OSI Layer 3?
• source and destination IP address

3. In a connectionless system, which of the following is correct?
• The destination is not contacted before a packet is sent.

4. Which IP packet field will prevent endless loops?
• time-to-live

5. Which portion of the network layer address does a router use to forward packets?
• network portion

6. Refer to the exhibit. Using the network in the exhibit, what would be the default gateway address for host A in the 192.133.219.0 network?
• 192.133.219.1

7. If the default gateway is configured incorrectly on the host, what is the impact on communications?
• The host can communicate with other hosts on the local network, but is unable to communicate with hosts on remote networks.

8. What is the purpose of a default gateway?
• identifies the device that allows local network computers to communicate with devices on other networks

9. What type of routing uses information that is manually entered into the routing table?
• static

10. When the destination network is not listed in the routing table of a Cisco router, what are two possible actions that the router might take? (Choose two.)
• The router discards the packet.
• The router forwards the packet out the interface indicated by the default route entry.

11. What are the key factors to consider when grouping hosts into a common network? (Choose three.)
• purpose
• geographic location
• ownership

12. What is a component of a routing table entry?
• the next-hop address

13. Which intermediary devices could be used to implement security between networks? (Choose two.)
• router
• firewall

14. What are three common problems with a large network? (Choose three.)
• too few broadcasts
• performance degradation
• security issues
• host identification


15. Refer to the exhibit. All devices shown in the exhibit have factory default settings. How many broadcast domains are represented in the topology that is shown?
• 4

16. Which three statements are true about routes and their use? (Choose three.)
* If the destination network is directly connected, the router forwards the packet to the destination host.
• If no route exists for the destination network and a default route is present, the packet is forwarded to the next-hop router.
• If the originating host has a default gateway configured, the packet for a remote network can be forwarded using that route.

17. Refer to the exhibit. A network administrator is troubleshooting a connectivity problem and needs to determine the address that is used to forward network packets out the network. Using the netstat -r command, the administrator would identify which address as the address to which all hosts send packets that are destined for an outside network?
• 10.10.10.6

18. Refer to the exhibit. A network administrator notices that there are too many broadcasts on the network. What two steps can the network administrator take to resolve this problem? (Choose two.)
• Replace S2 with a router.
• Subnet the 192.168.0.0 /24 network.

19. Refer to the exhibit. The network in the exhibit is fully operational. What two statements correctly describe the routing for the topology that is shown? (Choose two.)
• 192.168.0.2 is the next-hop address that is used by R3 to route a packet from the 10.0.0.0 network to the 172.16.0.0 network.
• 192.168.0.1 is the next-hop address that is used by R2 to route a packet from the 172.16.0.0 network to the 192.168.12.0 network.

20. What two characteristics are commonly associated with dynamic routing protocols? (Choose two.)
• provide routers with up-to-date routing tables
• consume bandwidth to exchange route information

21. What statement describes the purpose of a default route?
• A host uses a default route to transfer data to a host outside the local network when no other route to the destination exists.


Chapter 6

1
How many bits make up an IPv4 address?

128

64

48

32 **

2

Refer to the exhibit. A network administrator has to develop an IP addressing scheme that uses the 192.168.1.0 /24 address space. The network that contains the serial link has already been addressed out of a separate range. Each network will be allocated the same number of host addresses. Which network mask will be appropriate to address the remaining networks?

255.255.255.248

255.255.255.224

255.255.255.192 **

255.255.255.240

255.255.255.128

255.255.255.252

3

Refer to the exhibit. The network administrator has assigned the internetwork of LBMISS an address range of 192.168.10.0. This address range has been subnetted using a /29 mask. In order to accommodate a new building, the technician has decided to use the fifth subnet for configuring the new network (subnet zero is the first subnet). By company policies, the router interface is always assigned the first usable host address and the workgroup server is given the last usable host address. Which configuration should be entered into the workgroup server's properties to allow connectivity to the network?

IP address: 192.168.10.38 subnet mask: 255.255.255.240 default gateway: 192.168.10.39

IP address: 192.168.10.38 subnet mask: 255.255.255.240 default gateway: 192.168.10.33

IP address: 192.168.10.38 subnet mask: 255.255.255.248 default gateway: 192.168.10.33 **

IP address: 192.168.10.39 subnet mask: 255.255.255.248 default gateway: 192.168.10.31

IP address: 192.168.10.254 subnet mask: 255.255.255.0 default gateway: 192.168.10.1

4

Refer to the exhibit. Which network prefix will work with the IP addressing scheme shown in the graphic.

/24

/16

/20

/27 **

/25

/28

5

Refer to the exhibit. A network administrator discovers that host A is having trouble with Internet connectivity, but the server farm has full connectivity. In addition, host A has full connectivity to the server farm. What is a possible cause of this problem?

The router has an incorrect gateway.

Host A has an overlapping network address.

Host A has an incorrect default gateway configured.

Host A has an incorrect subnet mask.

NAT is required for the host A network. **

6
What subnet mask would a network administrator assign to a network address of 172.30.1.0 if it were possible to have up to 254 hosts?

255.255.0.0

255.255.255.0 **

255.255.254.0

255.255.248.0

7
Given the IP address and subnet mask of 172.16.134.64 255.255.255.224, which of the following would describe this address?

This is a useable host address.

This is a broadcast address.

This is a network address. **

This is not a valid address.

8
What three facts are true about the network portion of an IPv4 address? (Choose three.)

identifies an individual device

is identical for all hosts in a broadcast domain

is altered as packet is forwarded **

varies in length **

is used to forward packets **

uses flat addressing

9
What is the network address of the host 172.25.67.99 /23 in binary?

10101100. 00011001.01000011.00000000

10101100. 00011001.01000011.11111111

10101100. 00011001.01000010.00000000 **

10101100. 00011001.01000010.01100011

10101100. 00010001.01000011. 01100010

10101100. 00011001.00000000.00000000

10
A router interface has been assigned an IP address of 172.16.192.166 with a mask of 255.255.255.248. To which subnet does the IP address belong?

172.16.0.0

172.16.192.0

172.16.192.128

172.16.192.160 **

172.16.192.168

172.16.192.176

11

Refer to the exhibit. Why would the response shown be displayed after issuing the command ping 127.0.0.1 on a PC?

The IP settings are not properly configured on the host. **

Internet Protocol is not properly installed on the host.

There is a problem at the physical or data link layer.

The default gateway device is not operating.

A router on the path to the destination host has gone down.

12
What two things will happen if a router receives an ICMP packet which has a TTL value of 1 and the destination host is several hops away? (Choose two.)

The router will discard the packet.

The router will decrement the TTL value and forward the packet to the next router on the path to the destination host.

The router will send a time exceeded message to the source host. **

The router will increment the TTL value and forward the packet to the next router on the path to the destination host.

The router will send an ICMP Redirect Message to the source host. **

13

Refer to the exhibit. An administrator is designing security rules for the 192.168.22.0 /24 network. Each security rule requires an address and mask pair to represent the machines that will be affected by the rule. Which two address and mask pairs will be the most precise way to reference the servers and hosts separately. (Choose two.)

192.168.22.40 255.255.255.248

192.168.22.40 255.255.255.252

192.168.22.100 255.255.255.128

192.168.22.100 255.255.255.254 **

192.168.22.1 255.255.255.192 **

192.168.22.101 255.255.255.224

14
Which of the following are features of IPv6? (Choose three.)

larger address space **

faster routing protocols

data types and classes of service **

authentication and encryption **

improved host naming conventions

same addressing scheme as IPv4

15
Which process do routers use to determine the subnet network address based upon a given IP address and subnet mask?

binary adding

hexadecimal anding

binary division

binary multiplication

binary ANDing **

16
What is the primary reason for development of IPv6?

security

header format simplification

expanded addressing capabilities **

addressing simplification

17
Which three IP addresses are private? (Choose three.)

172.168.33.1

10.35.66.70 **

192.168.99.5 **

172.18.88.90 **

192.33.55.89

172.35.16.5

18
Which statements are true regarding IP addressing? (Choose two.)

NAT translates public addresses to private addresses destined for the Internet.

Only one company is allowed to use a specific private network address space.

Private addresses are blocked from public Internet by router. **

Network 172.32.0.0 is part of the private address space.

IP address 127.0.0.1 can be used for a host to direct traffic to itself. **

19
Which IPv4 subnetted addresses represent valid host addresses? (Choose three.)

172.16.4.127 /26

172.16.4.155 /26 **

172.16.4.193 /26 **

172.16.4.95 /27

172.16.4.159 /27

172.16.4.207 /27 **