Networks

Pataasin ang iyong marka sa homework at exams ngayon gamit ang Quizwiz!

What characteristic describes antispyware?

applications that protect end devices from becoming infected with malicious software

Which two statements are correct in a comparison of IPv4 and IPv6 packet headers?

1. The Source Address field name from IPv4 is kept in IPv6. 2. The Time-to-Live field from IPv4 has been replaced by the Hop Limit field in IPv6.

What method is used to manage contention-based access on a wireless network?

CSMA/CA

What are two features of ARP?

1. 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. 2. If a device receiving an ARP request has the destination IPv4 address, it responds with an ARP reply.

Which two statements accurately describe an advantage or a disadvantage when deploying NAT for IPv4 in a network?

1. NAT provides a solution to slow down the IPv4 address depletion. 2. NAT introduces problems for some applications that require end-to-end connectivity.

What are two problems that can be caused by a large number of ARP request and reply messages?

1. A large number of ARP request and reply messages may slow down the switching process, leading the switch to make many changes in its MAC table. 2. The ARP request is sent as a broadcast, and will flood the entire subnet.

What are three characteristics of the CSMA/CD process?

1. After detecting a collision, hosts can attempt to resume transmission after a random time delay has expired. 2. All of the devices on a segment see data that passes on the network medium. 3. A device listens and waits until the media is not busy before transmitting.

Which two statements describe how to assess traffic flow patterns and network traffic types using a protocol analyzer?

1. Capture traffic during peak utilization times to get a good representation of the different traffic types. 2. Perform the capture on different network segments. (Traffic flow patterns should be gathered during peak utilization times to get a good representation of the different traffic types. The capture should also be performed on different network segments because some traffic will be local to a particular segment.)

An administrator defined a local user account with a secret password on router R1 for use with SSH. Which three additional steps are required to configure R1 to accept only encrypted SSH connections?

1. Configure the IP domain name on the router. 2. Generate the SSH keys. 3. Enable inbound vty SSH sessions. (There are four steps to configure SSH support on a Cisco router:Step 1: Set the domain name.Step 2: Generate one-way secret keys.Step 3: Create a local username and password.Step 4: Enable SSH inbound on a vty line.)

Which two statements are correct about MAC and IP addresses during data transmission if NAT is not involved?

1. Destination and source MAC addresses have local significance and change every time a frame goes from one LAN to another. 2. Destination IP addresses in a packet header remain constant along the entire path to a target host.

Which two statements describe features of an IPv4 routing table on a router?

1. Directly connected interfaces will have two route source codes in the routing table: C and S . 2. If a default static route is configured in the router, an entry will be included in the routing table with source code S .

A network technician is researching the use of fiber optic cabling in a new technology center. Which two issues should be considered before implementing fiber optic media?

1. Fiber optic cabling requires different termination and splicing expertise from what copper cabling requires. 2. Fiber optic provides higher data capacity but is more expensive than copper cabling.

Data is being sent from a source PC to a destination server. Which three statements correctly describe the function of TCP or UDP in this situation? (Choose three.)

1. The source port field identifies the running application or service that will handle data returning to the PC. 2. UDP segments are encapsulated within IP packets for transport across the network. 3. The UDP destination port number identifies the application or service on the server which will handle the data.

What are the two most effective ways to defend against malware?

1. Update the operating system and other application software. 2. Install and update antivirus software. (A cybersecurity specialist must be aware of the technologies and measures that are used as countermeasures to protect the organization from threats and vulnerabilities.)

What are two primary responsibilities of the Ethernet MAC sublayer?

1. accessing the media 2. data encapsulation

What are two functions that are provided by the network layer?

1. directing data packets to destination hosts on other networks 2. providing end devices with a unique network identifier

What are two characteristics of IP?

1. does not require a dedicated end-to-end connection 2. operates independently of the network media (The Internet Protocol (IP) is a connectionless, best effort protocol. This means that IP requires no end-to-end connection nor does it guarantee delivery of packets. IP is also media independent, which means it operates independently of the network media carrying the packets.)

Which two functions are performed at the MAC sublayer of the OSI Data Link Layer to facilitate Ethernet communication?

1. integrates Layer 2 flows between 10 Gigabit Ethernet over fiber and 1 Gigabit Ethernet over copper 2. implements CSMA/CD over legacy shared half-duplex media

What are two common causes of signal degradation when using UTP cabling?

1. low-quality cable or connectors 2. improper termination

Which two functions are performed at the LLC sublayer of the OSI Data Link Layer to facilitate Ethernet communication?

1. places information in the Ethernet frame that identifies which network layer protocol is being encapsulated by the frame 2. enables IPv4 and IPv6 to utilize the same physical medium

What would be the interface ID of an IPv6 enabled interface with a MAC address of 1C-6F-65-C2-BD-F8 when the interface ID is generated by using the EUI-64 process?

1E6F:65FF:FEC2:BDF8

What is the subnet ID associated with the IPv6 address 2001:DA48:FC5:A4:3D1B::1/64?

2001:DA48:FC5:A4::/64​ (The /64 represents the network and subnet IPv6 fields. The fourth field of hexadecimal digits is referred to as the subnet ID. The subnet ID for this address is 2001:DA48:FC5:A4::0/64.)

A network administrator is adding a new LAN to a branch office. The new LAN must support 200 connected devices. What is the smallest network mask that the network administrator can use for the new network?

255.255.255.0

A network administrator is adding a new LAN to a branch office. The new LAN must support 61 connected devices. What is the smallest network mask that the network administrator can use for the new network?

255.255.255.192

What subnet mask is needed if an IPv4 network has 40 devices that need IP addresses and address space is not to be wasted?

255.255.255.192

A network administrator is adding a new LAN to a branch office. The new LAN must support 25 connected devices. What is the smallest network mask that the network administrator can use for the new network?

255.255.255.224

A network administrator wants to have the same network mask for all networks at a particular small site. The site has the following networks and number of devices: IP phones - 22 addressesPCs - 20 addresses neededPrinters - 2 addresses neededScanners - 2 addresses needed The network administrator has deemed that 192.168.10.0/24 is to be the network used at this site. Which single subnet mask would make the most efficient use of the available addresses to use for the four subnetworks?

255.255.255.224

A network administrator is adding a new LAN to a branch office. The new LAN must support 4 connected devices. What is the smallest network mask that the network administrator can use for the new network?

255.255.255.248

An organization is assigned an IPv6 address block of 2001:db8:0:ca00::/56. How many subnets can be created without using bits in the interface ID space?

256

Which type of server relies on record types such as A, NS, AAAA, and MX in order to provide services?

A DNS server stores records that are used to resolve IP addresses to host names. Some DNS record types include the following: A - an end device IPv4 address NS - an authoritative name server AAAA - an end device IPv6 address MX - a mail exchange record

What service is provided by HTTP?

A basic set of rules for exchanging text, graphic images, sound, video, and other multimedia files on the web.

Which scenario describes a function provided by the transport layer?

A student has two web browser windows open in order to access two web sites. The transport layer ensures the correct web page is delivered to the correct browser window. (The source and destination port numbers are used to identify the correct application and window within that application.)

What service is provided by Internet Messenger?

An application that allows real-time chatting among remote users.

What happens when the "transport input ssh" command is entered on the switch vty lines?

Communication between the switch and remote users is encrypted.

A client packet is received by a server. The packet has a destination port number of 67. What service is the client requesting?

DHCP

A client packet is received by a server. The packet has a destination port number of 53. What service is the client requesting?

DNS

A user is attempting to access http://www.cisco.com/ without success. Which two configuration values must be set on the host to allow this access?

DNS server default gateway

A network administrator notices that some newly installed Ethernet cabling is carrying corrupt and distorted data signals. The new cabling was installed in the ceiling close to fluorescent lights and electrical equipment. Which two factors may interfere with the copper cabling and result in signal distortion and data corruption? (Choose two.)

EMI and RFI signals can distort and corrupt data signals that are carried by copper media. These distortions usually come from radio waves and electromagnetic devices such as motors and florescent lights. Crosstalk is a disturbance that is caused by adjacent wires bundled too close together with the magnetic field of one wire affecting another. Signal attenuation is caused when an electrical signal begins to deteriorate over the length of a copper cable.

A new network administrator has been asked to enter a banner message on a Cisco device. What is the fastest way a network administrator could test whether the banner is properly configured?

Exit privileged EXEC mode and press Enter.

Which range of link-local addresses can be assigned to an IPv6-enabled interface?​

FE80::/10

A client packet is received by a server. The packet has a destination port number of 21. What service is the client requesting?

FTP

Which subnet would include the address 192.168.1.96 as a usable host address?

For the subnet of 192.168.1.64/26, there are 6 bits for host addresses, yielding 64 possible addresses. However, the first and last subnets are the network and broadcast addresses for this subnet. Therefore, the range of host addresses for this subnet is 192.168.1.65 to 192.168.1.126. The other subnets do not contain the address 192.168.1.96 as a valid host address.

A client packet is received by a server. The packet has a destination port number of 80. What service is the client requesting?

HTTP

What two pieces of information are displayed in the output of the "show ip interface brief" command?

IP addresses Layer 1 statuses The command show ip interface brief shows the IP address of each interface, as well as the operational status of the interfaces at both Layer 1 and Layer 2. In order to see interface descriptions and speed and duplex settings, use the command show running-config interface. Next-hop addresses are displayed in the routing table with the command show ip route, and the MAC address of an interface can be seen with the command show interfaces.

A DNS server stores records that are used to resolve IP addresses to host names. Some DNS record types include the following: A - an end device IPv4 address NS - an authoritative name server AAAA - an end device IPv6 address MX - a mail exchange record

If the same mask is to be used, then the network with the most hosts must be examined for the number of hosts, which in this case is 22 hosts. Thus, 5 host bits are needed. The /27 or 255.255.255.224 subnet mask would be appropriate to use for these networks.

What mechanism is used by a router to prevent a received IPv4 packet from traveling endlessly on a network?

It decrements the value of the TTL field by 1 and if the result is 0, it discards the packet and sends a Time Exceeded message to the source host.

What is an advantage to using a protocol that is defined by an open standard?

It encourages competition and promotes choices. (A monopoly by one company is not a good idea from a user point of view. If a protocol can only be run on one brand, it makes it difficult to have mixed equipment in a network. A proprietary protocol is not free to use. An open standard protocol will in general be implemented by a wide range of vendors.)

A client is using SLAAC to obtain an IPv6 address for its interface. After an address has been generated and applied to the interface, what must the client do before it can begin to use this IPv6 address?

It must send an ICMPv6 Neighbor Solicitation message to ensure that the address is not already in use on the network.

What is one main characteristic of the data link layer?

It shields the upper layer protocol from being aware of the physical medium to be used in the communication.

A host is trying to send a packet to a device on a remote LAN segment, but there are currently no mappings in its ARP cache. How will the device obtain a destination MAC address?

It will send an ARP request for the MAC address of the default gateway.

A host is trying to send a packet to a device on a remote LAN segment, but there are currently no mappings in the ARP cache. How will the device obtain a destination MAC address?

It will send an ARP request for the MAC address of the default gateway.

What service is provided by BOOTP?

Legacy application that enables a diskless workstation to discover its own IP address and find a BOOTP server on the network.

Match each description with an appropriate IP address.

Link-Local addresses are assigned automatically by the OS environment and are located in the block 169.254.0.0/16. The private addresses ranges are 10.0.0.0/8, 172.16.0.0/12, and 192.168.0.0/16. TEST-NET addresses belong to the range 192.0.2.0/24. The addresses in the block 240.0.0.0 to 255.255.255.254 are reserved as experimental addresses. Loopback addresses belong to the block 127.0.0.0/8.

What attribute of a NIC would place it at the data link layer of the OSI model?

MAC address

What is an advantage for small organizations of adopting IMAP instead of POP?

Messages are kept in the mail servers until they are manually deleted from the email client. (Explanation: IMAP and POP are protocols that are used to retrieve email messages. The advantage of using IMAP instead of POP is that when the user connects to an IMAP-capable server, copies of the messages are downloaded to the client application. IMAP then stores the email messages on the server until the user manually deletes those messages.)

Which two protocols operate at the top layer of the TCP/IP protocol suite?

POP DNS

A client packet is received by a server. The packet has a destination port number of 110. What service is the client requesting?

POP3

What service is provided by DNS?

Resolves domain names, such as cisco.com, into IP addresses.

What service is provided by POP3?

Retrieves email from the server by downloading the email to the local mail application of the client.

What are two ICMPv6 messages that are not present in ICMP for IPv4?

Router Advertisement Neighbor Solicitation

A network administrator needs to keep the user ID, password, and session contents private when establishing remote CLI connectivity with a switch to manage it. Which access method should be chosen?

SSH

Match the application protocols to the correct transport protocols.

TCP: FTP, HTTP, SMTP UDP: DHCP, TFTP

A client packet is received by a server. The packet has a destination port number of 69. What service is the client requesting?

TFTP

What is the consequence of configuring a router with the ipv6 unicast-routing global configuration command?

The IPv6 enabled router interfaces begin sending ICMPv6 Router Advertisement messages.

What is the consequence of configuring a router with the ipv6 unicast-routing global configuration command?​

The IPv6 enabled router interfaces begin sending ICMPv6 Router Advertisement messages.

An IPv6 enabled device sends a data packet with the destination address of FF02::2. What is the target of this packet?​

all IPv6 configured routers on the local link​

Refer to the exhibit. An administrator is trying to configure the switch but receives the error message that is displayed in the exhibit. What is the problem?

The administrator must first enter privileged EXEC mode before issuing the command

A technician with a PC is using multiple applications while connected to the Internet. How is the PC able to keep track of the data flow between multiple application sessions and have each application receive the correct packet flows?

The data flow is being tracked based on the source port number that is used by each application. (The source port number of an application is randomly generated and used to individually keep track of each session connecting out to the Internet. Each application will use a unique source port number to provide simultaneous communication from multiple applications through the Internet.)

What will happen if the default gateway address is incorrectly configured on a host?

The host cannot communicate with hosts in other networks.

How does the service password-encryption command enhance password security on Cisco routers and switches?

The service password-encryption command encrypts plaintext passwords in the configuration file so that they cannot be viewed by unauthorized users.

The global configuration command ip default-gateway 172.16.100.1 is applied to a switch. What is the effect of this command?

The switch can be remotely managed from a host on another network. (A default gateway address is typically configured on all devices to allow them to communicate beyond just their local network. In a switch this is achieved using the command ip default-gateway <ip address>.)

Refer to the exhibit. What is wrong with the displayed termination?

The untwisted length of each wire is too long.

Which value, that is contained in an IPv4 header field, is decremented by each router that receives a packet?

Time-to-Live

Which type of security threat would be responsible if a spreadsheet add-on disables the local software firewall?

Trojan horse (A Trojan horse is software that does something harmful, but is hidden in legitimate software code. A denial of service (DoS) attack results in interruption of network services to users, network devices, or applications. A brute-force attack commonly involves trying to access a network device. A buffer overflow occurs when a program attempts to store more data in a memory location than it can hold.)

What service is provided by HTTPS?

Uses encryption to secure the exchange of text, graphic images, sound, and video on the web.

Which wireless technology has low-power and data rate requirements making it popular in home automation applications?

ZigBee

Which wireless technology has low-power and low-data rate requirements making it popular in IoT environments?

Zigbee (Zigbee is a specification used for low-data rate, low-power communications. It is intended for applications that require short-range, low data-rates and long battery life. Zigbee is typically used for industrial and Internet of Things (IoT) environments such as wireless light switches and medical device data collection.)

What characteristic describes a VPN?

a tunneling protocol that provides remote users with secure access into the network of an organization

Which three layers of the OSI model map to the application layer of the TCP/IP model?

application session presentation

Three bank employees are using the corporate network. The first employee uses a web browser to view a company web page in order to read some announcements. The second employee accesses the corporate database to perform some financial transactions. The third employee participates in an important live audio conference with other corporate managers in branch offices. If QoS is implemented on this network, what will be the priorities from highest to lowest of the different data types?

audio conference, financial transactions, web page (QoS mechanisms enable the establishment of queue management strategies that enforce priorities for different categories of application data. Thus, this queuing enables voice data to have priority over transaction data, which has priority over web data.)

A company has a file server that shares a folder named Public. The network security policy specifies that the Public folder is assigned Read-Only rights to anyone who can log into the server while the Edit rights are assigned only to the network admin group. Which component is addressed in the AAA network service framework?

authorization (After a user is successfully authenticated (logged into the server), the authorization is the process of determining what network resources the user can access and what operations (such as read or edit) the user can perform.)

Which frame field is created by a source node and used by a destination node to ensure that a transmitted data signal has not been altered by interference, distortion, or signal loss?

frame check sequence field

Which layer of the TCP/IP model provides a route to forward messages through an internetwork?

internet

What two security solutions are most likely to be used only in a corporate environment?

intrusion prevention systems virtual private networks

What command can be used on a Windows PC to see the IP configuration of that computer?

ipconfig

What does the term "attenuation" mean in data communication?

loss of signal strength as distance increases (Data is transmitted on copper cables as electrical pulses. A detector in the network interface of a destination device must receive a signal that can be successfully decoded to match the signal sent. However, the farther the signal travels, the more it deteriorates. This is referred to as signal attenuation.)

What characteristic describes a Trojan horse?

malicious software or code running on an end device

What characteristic describes a virus?

malicious software or code running on an end device

What three requirements are defined by the protocols used in network communcations to allow message transmission across a network? (Choose three.)

message encoding delivery options message size

What two ICMPv6 message types must be permitted through IPv6 access control lists to allow resolution of Layer 3 addresses to Layer 2 MAC addresses?

neighbor advertisements neighbor solicitations

A technician can ping the IP address of the web server of a remote company but cannot successfully ping the URL address of the same web server. Which software utility can the technician use to diagnose the problem?

nslookup (Traceroute (tracert) is a utility that generates a list of hops that were successfully reached along the path from source to destination.This list can provide important verification and troubleshooting information. The ipconfig utility is used to display the IP configuration settings on a Windows PC. The Netstat utility is used to identify which active TCP connections are open and running on a networked host. Nslookup is a utility that allows the user to manually query the name servers to resolve a given host name. This utility can also be used to troubleshoot name resolution issues and to verify the current status of the name servers.)

A wired laser printer is attached to a home computer. That printer has been shared so that other computers on the home network can also use the printer. What networking model is in use?

peer-to-peer (P2P) (Peer-to-peer (P2P) networks have two or more network devices that can share resources such as printers or files without having a dedicated server.)

A group of Windows PCs in a new subnet has been added to an Ethernet network. When testing the connectivity, a technician finds that these PCs can access local network resources but not the Internet resources. To troubleshoot the problem, the technician wants to initially confirm the IP address and DNS configurations on the PCs, and also verify connectivity to the local router. Which three Windows CLI commands and utilities will provide the necessary information?

ping ipconfig nslookup The ipconfig and nslookup commands will provide initial IP address and DNS configuration information to the technicians and determine if DHCP is assigning correct information to the PCs. The ping utility would be used to verify, or not, connectivity to the default gateway (router) using the configured default gateway address, or using the known correct default gateway address if these are found to be different. The arp -a or netsh interface ipv6 show neighbor commands could be used if the problem is then suspected to be an IP address to MAC address mapping issue. The telnet and tracert utilities could be used to determine where the problem was located in the network if the default gateway configuration was found to be correct.

What are three commonly followed standards for constructing and installing cabling?

pinouts cable lengths connector types

What are two characteristics shared by TCP and UDP?

port numbering use of checksum (Both TCP and UDP use source and destination port numbers to distinguish different data streams and to forward the right data segments to the right applications. Error checking the header and data is done by both protocols by using a checksum calculation to determine the integrity of the data that is received. TCP is connection-oriented and uses a 3-way handshake to establish an initial connection. TCP also uses window to regulate the amount of traffic sent before receiving an acknowledgment. UDP is connectionless and is the best protocol for carry digitized VoIP signals.)

What are proprietary protocols?

protocols developed by organizations who have control over their definition and operation (Proprietary protocols have their definition and operation controlled by one company or vendor. Some of them can be used by different organizations with permission from the owner. The TCP/IP protocol suite is an open standard, not a proprietary protocol.)

What is a function of the data link layer?

provides for the exchange of frames over a common local media

An employee of a large corporation remotely logs into the company using the appropriate username and password. The employee is attending an important video conference with a customer concerning a large sale. It is important for the video quality to be excellent during the meeting. The employee is unaware that after a successful login, the connection to the company ISP failed. The secondary connection, however, activated within seconds. The disruption was not noticed by the employee or other employees.What three network characteristics are described in this scenario? (Choose three.)

quality of service fault tolerance security

A disgruntled employee is using some free wireless networking tools to determine information about the enterprise wireless networks. This person is planning on using this information to hack the wireless network. What type of attack is this?

reconnaissance

Which two commands can be used on a Windows host to display the routing table?

route print netstat -r (On a Windows host, the route print or netstat -r commands can be used to display the host routing table. Both commands generate the same output. On a router, the show ip route command is used to display the routing table. The netstat -s command is used to display per-protocol statistics. The tracert command is used to display the path that a packet travels to its destination.)

A network administrator is designing the layout of a new wireless network. Which three areas of concern should be accounted for when building a wireless network? (Choose three.)

security interference coverage area

What characteristic describes spyware?

software that is installed on a user device and collects information about the user

When a switch configuration includes a user-defined error threshold on a per-port basis, to which switching method will the switch revert when the error threshold is reached?

store-and-forward

Which switching method drops frames that fail the FCS check?

store-and-forward switching

What are the three parts of an IPv6 global unicast address?

subnet ID global routing prefix interface ID

During the process of forwarding traffic, what will the router do immediately after matching the destination IP address to a network on a directly connected routing table entry?

switch the packet to the directly connected interface

A user sends an HTTP request to a web server on a remote network. During encapsulation for this request, what information is added to the address field of a frame to indicate the destination?

the MAC address of the default gateway

Which information does the show startup-config command display?​

the contents of the saved configuration file in the NVRAM

Users are reporting longer delays in authentication and in accessing network resources during certain time periods of the week. What kind of information should network engineers check to find out if this situation is part of a normal network behavior?

the network performance baseline

What characteristic describes identity theft?

the use of stolen credentials to access private data

Why would a Layer 2 switch need an IP address?

to enable the switch to be managed remotely (A switch, as a Layer 2 device, does not need an IP address to transmit frames to attached devices. However, when a switch is accessed remotely through the network, it must have a Layer 3 address. The IP address must be applied to a virtual interface rather than to a physical interface. Routers, not switches, function as default gateways.)

A user is complaining that an external web page is taking longer than normal to load.The web page does eventually load on the user machine. Which tool should the technician use with administrator privileges in order to locate where the issue is in the network?

tracert

What is the purpose of the TCP sliding window?

twisting the wires together into pairs (To help prevent the effects of crosstalk, UTP cable wires are twisted together into pairs. Twisting the wires together causes the magnetic fields of each wire to cancel each other out.)

Which two traffic types use the Real-Time Transport Protocol (RTP)?

video voice

A user is executing a tracert to a remote device. At what point would a router, which is in the path to the destination device, stop forwarding the packet?

when the value in the TTL field reaches zero (When a router receives a traceroute packet, the value in the TTL field is decremented by 1. When the value in the field reaches zero, the receiving router will not forward the packet, and will send an ICMP Time Exceeded message back to the source.)

Users report that the network access is slow. After questioning the employees, the network administrator learned that one employee downloaded a third-party scanning program for the printer. What type of malware might be introduced that causes slow performance of the network?

worm


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