Chapter_4_Network Protocols and Services

Which message delivery option is used when all devices need to receive the same message simultaneously? > Duplex > Unicast > Multicast > Broadcast

> Broadcast *

What three application layer protocols are part of the TCP/IP protocol suite? (Choose three.) > ARP > DHCP > DNS > FTP > NAT > PPP

> DHCP * > DNS * > FTP *

What is the prefix length notation for the subnet mask 255.255.255.224? > /26 > /27 > /28 > /25

> /27 *

The graphic shows a network diagram as follows: PC A connects to switch S1, which connects to the G0/0 interface of router R1. PC B connects to switch S2, which connects to the G0/1 interface of router R1. A network analyst is connected to switch S2. The address of each device is as follows: PC A: 192.168.1.212 and FE80::1243:FEFE:8A43:2122 and 01-90-C0-E4-55-BB PC B: 192.168.2.101 and FE80::FBB2:E77A:D143 and 08-CB-8A-5C-D5-8A R1 G0/0:192.168.1.1 and FE80::1 and 00-D0-D3-BE-79-26 R1 G0/1: 192.168.2.1 and FE80::1 and 00-60-0F-B1-D1-11 Refer to the exhibit. A cybersecurity analyst is viewing captured ICMP echo request packets sent from host A to host B on switch S2. What is the source MAC address of Ethernet frames carrying the ICMP echo request packets? > 08-CB-8A-5C-D5-BA > 00-D0-D3-BE-79-26 > 00-60-0F-B1-D1-11 > 01-90-C0-E4-55-BB

> 00-60-0F-B1-D1-11 * (When router R1 receives the ICMP echo requests from host A it will forward the packets out interface G0/1 towards host B. However, before forwarding the packets, R1 will encapsulate them in a new Ethernet frame using the MAC address of interface G0/1 as the source and the MAC address of host B as the destination.)

Which three IP addresses are private ? (Choose three.) > 192.167.10.10 > 10.1.1.1 > 192.168.5.5 > 172.16.4.4 > 172.32.5.2 > 224.6.6.6

> 10.1.1.1 * > 192.168.5.5 * > 172.16.4.4 * (The private IP addresses are within these three ranges: 10.0.0.0 - 10.255.255.255 172.16.0.0 - 172.31.255.255 192.168.0.0 - 192.168.255.255)

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? > 192.135.250.1 > 192.133.219.0 > 192.133.219.1 > 192.31.7.1

> 192.133.219.1 *

What is the most compressed representation of the IPv6 address 2001:0000:0000:abcd:0000:0000:0000:0001? > 2001::abcd::1 > 2001:0:abcd::1 > 2001::abcd:0:1 > 2001:0:0:abcd::1 > 2001:0000:abcd::1.

> 2001:0:0:abcd::1 *

Refer to the exhibit. What is the global IPv6 address of the host in uncompressed format? > 2001:0DB8:0000:0000:0BAF:0000:3F57:FE94 > 2001:0DB8:0000:0BAF:0000:0000:3F57:FE94 > 2001:DB80:0000:0000:BAF0:0000:3F57:FE94 > 2001:0DB8:0000:0000:0000:0BAF:3F57:FE94

> 2001:0DB8:0000:0000:0BAF:0000:3F57:FE94 *

How is a DHCPDISCOVER transmitted on a network to reach a DHCP server? > A DHCPDISCOVER message is sent with a multicast IP address that all DHCP servers listen to as the destination address. > A DHCPDISCOVER message is sent with the broadcast IP address as the destination address. > A DHCPDISCOVER message is sent with the IP address of the default gateway as the destination address. > A DHCPDISCOVER message is sent with the IP address of the DHCP server as the destination address.

> A DHCPDISCOVER message is sent with the broadcast IP address as the destination address. * (The DHCPDISCOVER message is sent by a DHCPv4 client and targets a broadcast IP along with the destination port 67. The DHCPv4 server or servers respond to the DHCPv4 clients by targeting port 68.)

Which message does an IPv4 host use to reply when it receives a DHCPOFFER message from a DHCP server? > DHCPACK > DHCPREQUEST > DHCPDISCOVER > DHCPOFFER

> DHCPREQUEST * (When the client receives the DHCPOFFER from the server, it sends back a DHCPREQUEST broadcast message. On receiving the DHCPREQUESTmessage, the server replies with a unicast DHCPACK message.)

What addresses are mapped by ARP? > Destination IPv4 address to the source MAC address > Destination IPv4 address to the destination hostname > Destination MAC address to the source IPv4 address > Destination MAC address to a destination IPv4 address

> Destination MAC address to a destination IPv4 address * (ARP, or the Address Resolution Protocol, works by mapping a destination MAC address to a destination IPv4 address. The host knows the destination IPv4 address and uses ARP to resolve the corresponding destination MAC address.)

Which two characteristics are associated with UDP sessions? (Choose two.) > Unacknowledged data packets are retransmitted. > Destination devices receive traffic with minimal delay. > Destination devices reassemble messages and pass them to an application. > Transmitted data segments are tracked. > Received data is unacknowledged.

> Destination devices receive traffic with minimal delay. * > Received data is unacknowledged. * (TCP: • Provides tracking of transmitted data segments • Destination devices will acknowledge received data. • Source devices will retransmit unacknowledged data. UDP • Destination devices will not acknowledge received data • Headers use very little overhead and cause minimal delay.)

Which application layer protocol uses message types such as GET, PUT, and POST? > SMTP > POP3 > DHCP > HTTP > DNS

> HTTP * (The GET command is a client request for data from a web server. A PUT command uploads resources and content, such as images, to a web server. A POST command uploads data files to a web server.)

What are two features of ARP? (Choose two.) > An ARP request is sent to all devices on the Ethernet LAN and contains the IP address of the destination host and its multicast MAC address. > If no device responds to the ARP request, then the originating node will broadcast the data packet to all devices on the network segment. > When a host is encapsulating a packet into a frame, it refers to the MAC address table to determine the mapping of IP addresses to MAC addresses. > If a host is ready to send a packet to a local destination device and it has the IP address but not the MAC address of the destination, it generates an ARP broadcast. > If a device receiving an ARP request has the destination IPv4 address, it responds with an ARP reply.

> If a host is ready to send a packet to a local destination device and it has the IP address but not the MAC address of the destination, it generates an ARP broadcast. * > If a device receiving an ARP request has the destination IPv4 address, it responds with an ARP reply. *

What are two potential network problems that can result from ARP operation? (Choose two.) > Multiple ARP replies result in the switch MAC address table containing entries that match the MAC addresses of hosts that are connected to the relevant switch port. > Network attackers could manipulate MAC address and IP address mappings in ARP messages with the intent of intercepting network traffic. > On large networks with low bandwidth, multiple ARP broadcasts could cause data communication delays. > Manually configuring static ARP associations could facilitate ARP poisoning or MAC address spoofing. > Large numbers of ARP request broadcasts could cause the host MAC address table to overflow and prevent the host from communicating on the network.

> Network attackers could manipulate MAC address and IP address mappings in ARP messages with the intent of intercepting network traffic. * > On large networks with low bandwidth, multiple ARP broadcasts could cause data communication delays. *

The exhibit shows a network topology. PC1 and PC2 are connected to the Fa0/1 and Fa0/2 ports of the SW1 switch, respectively. SW1 is connected through its Fa0/3 port to the Fa0/0 interface of the RT1 router. RT1 is connected through its Fa0/1 to the Fa0/2 port of SW2 switch. SW2 is connected through its Fa0/1 port to the PC3. Refer to the exhibit. PC1 issues an ARP request because it needs to send a packet to PC2. In this scenario, what will happen next? > SW1 will send an ARP reply with the PC2 MAC address. > PC2 will send an ARP reply with its MAC address. > RT1 will send an ARP reply with its Fa0/0 MAC address. > RT1 will send an ARP reply with the PC2 MAC address. > SW1 will send an ARP reply with its Fa0/1 MAC address.

> PC2 will send an ARP reply with its MAC address. *

PC1 and PC3 are on different networks separated by a router, RT1. PC1 issues an ARP request because it needs to send a packet to PC3. In this scenario, what will happen next? > RT1 will forward the ARP request to PC3. > RT1 will drop the ARP request. > RT1 will send an ARP reply with its own MAC address. > RT1 will send an ARP reply with the PC3 MAC address.

> RT1 will send an ARP reply with its own MAC address. * (When a network device has to communicate with a device on another network, it broadcasts an ARP request asking for the default gateway MAC address. The default gateway (RT1) unicasts an ARP reply with its MAC address)

Which transport layer feature is used to guarantee session establishment? > UDP sequence number > TCP 3-way handshake > TCP port number > UDP ACK flag

> TCP 3-way handshake *

Which statement is true about the TCP/IP and OSI models? > The TCP/IP transport layer and OSI Layer 4 provide similar services and functions. > The TCP/IP network access layer has similar functions to the OSI network layer. > The OSI Layer 7 and the TCP/IP application layer provide identical functions. > The first three OSI layers describe general services that are also provided by the TCP/IP Internet layer.

> The TCP/IP transport layer and OSI Layer 4 provide similar services and functions. *

Which statement is true about FTP? > The client can download data from or upload data to the server. > The client can choose if FTP is going to establish one or two connections with the server. > FTP is a peer-to-peer application. > FTP does not provide reliability during data transmission.

> The client can download data from or upload data to the server. * (FTP is a client/server protocol. FTP requires two connections between the client and the server and uses TCP to provide reliable connections. With FTP, data transfer can happen in either direction. The client can download (pull) data from the server or upload (push) data to the server.)

If the default gateway is configured incorrectly on the host, what is the impact on communications? > The host is unable to communicate on the local network. > There is no impact on communications. > The host can communicate with other hosts on remote networks, but is unable to communicate with hosts on the local network. > The host can communicate with other hosts on the local network, but isunable to communicate with hosts on remote networks.

> The host can communicate with other hosts on the local network, but isunable to communicate with hosts on remote networks. *

What happens if part of an FTP message is not delivered to the destination? > The message is lost because FTP does not use a reliable delivery method. > The part of the FTP message that was lost is re-sent. > The FTP source host sends a query to the destination host. > The entire FTP message is re-sent.

> The part of the FTP message that was lost is re-sent. *

A high school in New York (school A) is using videoconferencing technology to establish student interactions with another high school (school B) in Russia. The videoconferencing is conducted between two end devices through the Internet. The network administrator of school A configures the end device with the IP address 209.165.201.10. The administrator sends a request for the IP address for the end device in school B and the response is 192.168.25.10. Neither school is using a VPN. The administrator knows immediately that this IP will not work. Why? > This is a link-local address. > This is a loopback address. > There is an IP address conflict. > This is a private IP address.

> This is a private IP address.*

What OSI layer is responsible for establishing a temporary communication session between two applications and ensuring that transmitted data can be reassembled in proper sequence? > Session > Transport > Network > Data link

> Transport *

Which two OSI model layers have the same functionality as two layers of the TCP/IP model? (Choose two.) > Session > Transport > Network > Data link > Physical

> Transport * > Network * (The OSI transport layer is functionally equivalent to the TCP/IP transport layer, and the OSI network layer is equivalent to the TCP/IP Internet layer)

What part of the URL, http://www.cisco.com/index.html, represents the top-level DNS domain? > www > http > index > com

> com * (The components of the URL http://www.cisco.com/index.htm are as follows: http = protocol www = part of the server name cisco = part of the domain name index = file name com = the top-level domain)

What is the primary purpose of NAT? > conserve IPv4 addresses > allow peer-to-peer file sharing > enhance network performance > increase network security

> conserve IPv4 addresses * (developed to conserve IPv4 addresses. A side benefit is that NAT adds a small level of security by hiding the internal network addressing scheme. However, there are some drawbacks of using NAT. It does not allow true peer-to-peer communication and it adds latency to outbound connections.)

Which term is used to describe the process of placing one message format inside another message format? > encoding > multiplexing > encapsulation > segmentation

> encapsulation *

Which PDU format is used when bits are received from the network medium by the NIC of a host? > frame > file > packet > segment

> frame *

In NAT translation for internal hosts, what address would be used by external users to reach internal hosts? > outside global > outside local > inside local > inside global

> inside global * (From the perspective of a NAT device, inside global addresses are used by external users to reach internal hosts. Inside local addresses are the addresses assigned to internal hosts. Outside global addresses are the addresses of destinations on the external network. Outside local addresses are the actual private addresses of destination hosts behind other NAT devices.)

Refer to the exhibit. A cybersecurity analyst is viewing captured packets forwarded on switch S1. Which device has the MAC address 50:6a:03:96:71:22? > PC-A > router DG > DSN server > router ISP > web server

> router DG * (The Wireshark capture is of a DNS query from PC-A to the DNS server. Because the DNS server is on a remote network, the PC will send the query to the default gateway router, router DG, using the MAC address of the router G0/0 interface on the router.)

Which TCP mechanism is used to identify missing segments? > sequence numbers > FCS > acknowledgments > window size

> sequence numbers *

What is a socket? > the combination of the source and destination sequence numbers and port numbers > the combination of a source IP address and port number or a destination IP address and port number > the combination of the source and destination sequence and acknowledgment numbers > the combination of the source and destination IP address and source and destination Ethernet address

> the combination of a source IP address and port number or a destination IP address and port number *

Why does a Layer 3 device perform the ANDing process on a destination IP address and subnet mask? > to identify the network address of the destination network > to identify the host address of the destination host > to identify the broadcast address of the destination network > to identify faulty frames

> to identify the network address of the destination network *

What is the purpose of ICMP messages? > to provide feedback of IP packet transmissions > to monitor the process of a domain name to IP address resolution > to inform routers about network topology changes > to ensure the delivery of an IP packet

> to provide feedback of IP packet transmissions *

What is the purpose of the routing process? > to provide secure Internet file transfer > to convert a URL name into an IP address > to forward traffic on the basis of MAC addresses > to encapsulate data that is used to communicate across a network > to select the paths that are used to direct traffic to destination networks

> to select the paths that are used to direct traffic to destination networks *