Network Essentials

What command will prevent all unencrypted passwords from displaying in plain text in a configuration file?

(config)# service password-encryption

Which three IP addresses are considered private addresses?

10.0.0.0 - 10.255.255.255 172.16.0.0 - 172.31.255.255 192.168.0.0 - 192.168.255.255

When a computer assembles a frame to be sent over the network, what is the maximum size of an Ethernet frame?

1518 bytes

Which address is a valid IPv6 address that could be assigned to a host?

2001:db8:0:1111::200/120​

What is the decimal equivalent to binary 11110000?

240

Which statement describes a major characteristic of a local area network?

A LAN is under one administrative control.

What are two functions of a router?

A router connects multiple IP networks. It determines the best path to send packets.

Which scenario describes a peer-to-peer network?

A user has shared a printer attached to the workstation.

When a LAN is connected to the internet using a wireless router, how do devices on the LAN communicate on the internet using NAT?

All devices must share the single public IPv4 address assigned to the wireless router in order to communicate to the internet via NAT.

What is the difference between the terms bandwidth and throughput?

Bandwidth is the capacity of data transfer in a network and throughput is the actual data transfer rate.

A user is looking for a wireless headphone for listening to songs stored on a smartphone. What wireless technology would the headphone use?

Bluetooth

What is a difference between the functions of Cloud computing and virtualization?

Cloud computing separates the application from the hardware whereas virtualization separates the OS from the underlying hardware.

A DHCP configured PC boots up. What is the order of the messages that are sent and received by this PC in order to obtain an appropriate IP address?

DHCPDISCOVER, DHCPOFFER, DHCPREQUEST, DHCPACK

A law firm uses DHCPv4 to dynamically assign IPv4 addresses for staff workstations. The DHCP policy specifies that the lease period is 7 days. A staff member returns to the office after 2 weeks of vacation. When the employee turns on the workstation, which DHCPv4 message is sent by the workstation to obtain a valid IPv4 address?

DHCPREQUEST unicast message

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 company uses DHCP servers to dynamically assign IPv4 addresses to employee workstations. The address lease duration is set as 5 days. An employee returns to the office after an absence of one week. When the employee boots the workstation, it sends a message to obtain an IP address. Which Layer 2 and Layer 3 destination addresses will the message contain?

FF-FF-FF-FF-FF-FF and 255.255.255.255

Which three protocols operate at the application layer of the TCP/IP model?

FTP, DHCP, and POP3

Which two steps are required before SSH can be enabled on a Cisco router?

Give the router a host name and domain name. Generate a set of secret keys to be used for encryption and decryption.

When designing an IP address scheme, what is a benefit of using DHCP to assign host addresses?

Hosts are permanently assigned an address by the DHCP server so that they are easier to manage

What benefit does DHCP provide to a network?

Hosts can connect to the network and get an IP address without manual configuration.

Which two application layer protocols manage the exchange of messages between a client with a web browser and a remote web server?

Hypertext Transfer Protocol (HTTP) and HTTP Secure (HTTPS)

Which three acronyms/initialisms represent standards organizations?

IEEE IANA IETF

A technician uses an application to capture packets on the network. One such capture reveals the password that is used by a person in the classroom to initiate a Telnet session with a school network device. What recommendation could the technician make to the person who is using Telnet?

If possible, enable the network device to use SSH instead of Telnet.

What does the letter C mean next to an entry in the output of the show ip route command?

It identifies a network that is directly connected to the router.

A company has a few employees that are designers. The designers do not have the CAD application loaded on their local computer. Instead, the designers use a CAD application hosted by the application developer. Which type of virtualization is the company using?

It is likely that someone attempted a DoS attack.

Which feature is characteristic of MAC filtering in wireless networks?

It restricts computer access to a wireless network.

Which two statements about a Service Set Identifier (SSID) are true?

It tells a wireless device to which WLAN it belongs. All wireless devices on the same WLAN must have the same SSID.

Which function does NAT perform in a wireless router?

NAT takes an internal source IP address and translates it to a global IP address.

Which memory location on a Cisco router or switch stores the startup configuration file?

NVRAM

What is a benefit of using cloud computing in networking?

Network capabilities are extended without requiring investment in new infrastructure, personnel, or software.

What is the first step that a switch performs during the bootup sequence?

POST is initiated.

Which two statements correctly describe the components of a router?

ROM contains diagnostics executed on hardware modules. Flash memory does not lose its contents during a reboot.

Which protocol is used by a server that needs to send an email message to another server in order to support successful delivery of the message?

SMTP

Which technology is used to uniquely identify a WLAN network?

SSID

What two default wireless router settings can affect network security?

The SSID is broadcast. A well-known administrator password is set.

A network administrator investigates a user problem. The user can reach hosts on the same network, but is unable to communicate to remote networks.The network administrator tries to ping the gateway address configured on the host device and is unsuccessful. What is the most likely cause of the problem?

The default gateway address is incorrect.

A user can access a file share resource on a server located in the same office but cannot access the internet. What is the possible cause?

The default gateway address is misconfigured on the PC.

A PC is not able to connect to a wired network. Pinging the loopback address is successful, but the gateway cannot be reached. On the network switch all the interface lights are on, except for the interface connected to the PC. The LED on the network card is off. What is the most likely cause of this problem?

The network cable is faulty.

What action does a DNS server take if it does not have an entry for a requested URL?

The server checks with another DNS server to see if it has an entry.

A new employee is attempting to configure a cell phone to connect to the email server of the company. What is the source port number when sending an email from a mobile device?

The source port number is 25.

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 user is setting up a home wireless network. A global address is to be used in NAT translations for traffic flowing through the wireless router. How is this global address assigned?

The wireless router will act as a DHCP client in order to receive global addressing from the ISP.

A medium-sized company uses APs, WLCs, and laptops for employee workstations. An employee reports the inability to connect to the Internet. A technician verifies that other workstations can successfully connect to the Internet. What are two possible reasons for the problem?

The workstation is out of range. The wireless client is not configured for DHCP.

What are two characteristics of 802.11 wireless networks?

They use CSMA/CA technology. Collisions can exist in the networks.

Which statement describes the ping and tracert commands?

Tracert shows each hop, while ping shows a destination reply only.

Which wireless security technology is difficult to crack and provides encryption of network traffic?

WPA2

Which type of network is covered by the IEEE 802.11 standards?

Wi-Fi

Which two methods are used to directly connect mobile devices such as tablets and smartphones to a data network?

Wi-Fi WiMax

Which security function is provided by a firewall?

allows or blocks traffic based on IP address, port number, or application

What are two benefits of wireless networks over wired networks?

anytime, anywhere connectivity mobility

Why does HTTP use TCP as the transport layer protocol?

because HTTP requires reliable delivery

When a router receives a packet, what information must be examined in order for the packet to be forwarded to a remote destination?

destination IP address

A message is sent to all hosts on a remote network. Which type of message is it?

directed broadcast

BASE

distance in meters

Which is a characteristic of a Type 2 hypervisor?​

does not require management console software

What is an advantage of the peer-to-peer network model?

ease of setup

What makes fiber preferable to copper cabling for interconnecting buildings?

greater distances per cable run limited susceptibility to EMI/RFI greater bandwidth potential

What does the IP address 172.17.4.250/24 represent?

host address

Which network design solution will best extend access layer connectivity to host devices?

implementing wireless connectivity

Which three features represent benefits of virtualization?

less power consumption improved disaster recovery less equipment

What type of address is automatically assigned to an interface when IPv6 is enabled on that interface?

link-local

What is the function of ARP?

maps IPv4 addresses to MAC addresses

Which function is supplied by the access layer in a three-layer network design?

network access

Users are complaining that they are unable to browse certain websites on the Internet. An administrator can successfully ping a web server via its IP address, but cannot browse to the domain name of the website. Which troubleshooting tool would be most useful in determining where the problem is?

nslookup

What technique is used in social engineering attacks?

phishing

Which two OSI model layers have the same functionality as a single layer of the TCP/IP model?

physical data link

A network security administrator is writing documentation on the firewall requirements for allowing Telnet access to the remote server. Which two pieces of information should be included?

port 23 TCP

A network administrator needs to monitor network traffic to and from servers in a data center. Which features of an IP addressing scheme should be applied to these devices?

predictable static IP addresses for easier identification

Which three layers of the OSI model make up the application layer of the TCP/IP model?

presentation application session

Which two devices are shared peripherals?

printer scanner

Which switch command would a network administrator use to determine if there are encapsulation or media errors on an interface?

show interfaces

100

speed Mbps

Which three configuration components are required to allow a host to communicate with other hosts on remote networks?

subnet mask IP address default gateway

What are three characteristics of UTP cabling?

susceptible to EMI and RFI easiest type of networking cable to install most commonly used networking cable

Which network device makes forwarding decisions based on the destination MAC address that is contained in the frame?

switch

Which network server is malfunctioning if a user can ping the IP address of a web server but cannot ping the web server host name?

the DNS server

Which three factors should be considered when choosing the appropriate network media?

the environment in which the media is installed the amount of data and the data transfer rate desired the distance between hosts that the media will connect

Which interface allows remote management of a Layer 2 switch?

the switch virtual interface

What is the purpose of the startup configuration file on a Cisco router?

to contain the commands that are used to initially configure a router on startup

A technician has been asked to troubleshoot a simple network problem that seems to be caused by software. Which troubleshooting approach should be used?

top-down

A technician is tasked with connecting a printer directly to the network and making it accessible to all staff in the general vicinity. What type of network cable is most likely used to connect the printer?

twisted-pair

A router with a valid operating system contains a configuration file stored in NVRAM. The configuration file has an enable secret password but no console password. When the router boots up, which mode will display?

user EXEC mode

A file is downloaded from the Internet. After the user opens the downloaded file, the hard drive crashes and all information on the computer is lost. What type of attack occurred?

virus

When is UDP preferred to TCP?

when segments must arrive in a very specific sequence to be processed successfully

In what situation would a Layer 2 switch have an IP address configured?

when the Layer 2 switch needs to be remotely managed

When would the Cisco IOS image held in ROM be used to boot the router?

when the full IOS cannot be found

Which three devices are considered intermediate devices in a network?

wireless access point switch router

Which two types of devices provide dynamic IPv4 addressing for internal hosts on a local network?

wireless router PC-based DHCP server

Which three attacks exploit vulnerabilities in software?

worms Trojan horses viruses