1.4 Network Addressing - Loopback and reserved, Default gateway, Virtual IP, Subnet mask, Subnetting, Address assignments
The IP addressing information received first
101. A client requests a new dynamic address and receives a response from two DHCP servers. Which of the following addressing information would the client use? A. The IP addressing information received last B. The IP addressing information from the highest server MAC address C. The IP addressing information from the highest server IP address D. The IP addressing information received first
DHCP scope availability
104. A company is experiencing exponential growth and has hired many new employees. New users are reporting they cannot log into their systems, even though they are on the same network. The technician can see physical connectivity to the network switch along with their MAC addresses. Which of the following should the technician check NEXT? A. VLAN routing B. Server-based firewall configuration issue C. Patch cable type D. DHCP scope availability
Exhausted dynamic scope
106. A network technician receives reports indicating some users are unable to gain access to any network resources. During troubleshooting, the technician discovers the workstations have an IP address of 169.254.x.x. Which of the following is the MOST likely cause? A. Expired IP address B. Exhausted dynamic scope C. Misconfigured VLSM D. Rogue DHCP server
/31
109. Which of the following would be the MOST efficient subnet mask for a point-to-point link? A. /28 B. /29 C. /31 D. /32
172.18.0.0/23
113. A network technician is creating a new subnet for 488 host machines. The technician is told to use a class B address scheme when making the subnet and is instructed to leave as much room as possible for additional subnets of the same size. Which of the following subnets would fulfill these requirements? A. 10.5.4.0/22 B. 10.233.2.0/23 C. 172.16.0.0/22 D. 172.18.0.0/23 E. 192.168.25.0/24
Not enough DHCP addresses have been allotted
137. Users are reporting issues with slow connection speeds and a loss of connectivity on the newly installed wireless network. The issues are intermittent but seem to occur most often around midday. Which of the following is the MOST likely cause? A. There is interference from small appliances B. The signal coverage area is too small C. Not enough DHCP addresses have been allotted D. The DNS cache on the users' computers has become corrupt
EUI-64 (Extended Unique Identifier-64)
14. A network technician wants to address PCs on a subnet with IPv6 in addition to IPv4. The subnet currently uses a DHCP server that only supports IPv4. Which of the following should the technician use to assign IPv6 addresses automatically without DHCP? A. APIPA B. MAC reservations C. EUI-64 D. IPv4 to IPv6 tunnel
172.16.80.1 - 172.16.87.254
15. A network administrator has been given a network of 172.16.85.0/21 and wants to know the usable range of IP addresses on that subnet. Which of the following indicates the correct IP address range? A. 172.16.80.0 - 172.16.85.254 B. 172.16.80.0 - 172.16.88.255 C. 172.16.80.1 - 172.16.87.254 D. 172.16.80.1 - 172.16.85.255
The marketing department should receive a /25 network. The R&D department should have 172.16.49.207 as a broadcast address. The legal department should have usable IPs ranging from 172.16.49.129 to 172.16.49.190.
176. A company is expanding and building a new remote branch office. Marketing will need 78 IP addresses, finance will need 150 IP addresses, legal will need 39 IP addresses, and R&D will need 12 IP addresses. The network administrator gives the technician a network of 172.16.48.0/23 and wants the technician to use VLSM for the design. Which of the following are possible solutions? (Choose three.) A. The marketing department should receive a /25 network. B. The R&D department should have 172.16.49.207 as a broadcast address. C. The R&D department should receive a /27 network. D. The finance department should have 172.16.49.127 as a broadcast address. E. The marketing department should have usable IPs ranging from 172.16.49.129 to 172.16.49.190. F. The legal department should have a first usable IP address of 172.16.49.190 G. The legal department should have usable IPs ranging from 172.16.49.129 to 172.16.49.190. H. The R&D department should have a last usable IP address of 172.16.49.190.
Enable DHCP guard to detect rogue servers
18. A network technician has discovered a rogue access point under an empty cubicle desk. Which of the following should the technician perform to ensure another cannot be placed on the network? A. Disable unused ports on switches B. Enable DHCP guard to detect rogue servers C. Configure WPA2 on all access points D. Use TACACS+ authentication
A virtual IP pointing to the active DB
187. A company's web-based application has a database that is set up for high availability in case of a failure. Which of the following is necessary to achieve this type of setup? A. A virtual IP pointing to the active DB B. A static IP pointing to the passive DB C. A private IP pointing to the web front end D. A private IP pointing to the web proxy
The new DHCP server's IP address was not added to the router's IP helper list.
2. A technician has deployed an additional DHCP server for redundancy. Clients in certain subnets are not receiving DHCP leases from the new DHCP server. Which of the following is the MOST likely cause? A. The new DHCP server's IP address was not added to the router's IP helper list. B. The new DHCP server is not receiving the requests from the clients. C. The ARP cache of the new DHCP server needs to be updated. D. The ARP table on the router needs to be cleared.
192.1.0.124/30
20. A network administrator wants to narrow the scope of a subnet to two usable IP addresses within a class C network. Which of the following is the correct CIDR notation? A. 10.10.50.0/30 B. 172.16.20.0/30 C. 192.1.0.124/30 D. 192.168.0.192/24 E. 192.170.10.0/24
The DHCP scope has been exhausted.
202. A home user has purchased a new smart TV to stream online video services. The smart TV is unable to connect to the wireless network after several attempts. After returning from vacation, the home user tries again and can connect the TV to the wireless network. However, the user notices a laptop is no longer able to connect to the network. Which of the following is the MOST likely cause? A. The DHCP scope has been exhausted. B. The security passcode has been changed. C. The SSID is hidden. D. The AP configuration was reset.
The router was configured with an incorrect subnet mask
21. A network administrator configures a router with the following IP address information: Gigabit Ethernet 1 Interface: 10.10.0.1/24 Serial 0 Interface: 10.10.0.253/30 Clients are connected to a switch on the gigabit Ethernet interface; the ISP is connected to the Serial 0 interface. When the router configuration is complete and client devices are reconfigured, all clients report that they are unable to connect to the Internet. Which of the following is the MOST likely reason? A. The router was configured with an incorrect IP address B. The router was configured with an incorrect default gateway C. The router was configured with an incorrect subnet mask D. The router was configured with an incorrect loopback address
Exhausted DHCP scope
210. A company hires some temporary workers. On day one, the temporary employees report they are unable to connect to the network. A network technician uses a packet analysis tool and finds that many clients are continuously sending out requests for an IP address, but many of them are not receiving a response. Which of the following could be the cause of this issue? A. Exhausted DHCP scope B. Untrusted SSL certificates C. Duplicate MAC addresses D. Incorrect firewall settings
Rouge DHCP server
220. A user does not have access to network services but has Internet access. The technician notices the computer has an IP address of 192.168.1.144 when the network is 10.10.10.0. Which of the following is MOST likely the issue? A. Rogue DHCP server B. Duplicate IP addresses C. Incorrect gateway D. Server permission changes
DHCP Scope
23. A technician has installed multiple new PC clients and is connecting them to the network. Only one client is receiving IP addressing information. Which of the following should the technician verify as the NEXT troubleshooting step? A. DHCP scope B. DHCP lease C. Default gateway D. DNS zone
192.168.1.62
231. A technician is allocating the IP address space needed for a new remote office. This office will contain the engineering staff with six employees and the digital marketing staff with 55 employees. The technician has decided to allocate the 192.168.1.0/24 block to the remote office. The engineering staff has been allocated the 192.168.1.64/29 subnet. Using the LEAST amount of space possible, which of the following would be the last usable IP address in the engineering subnet? A. 192.168.1.62 B. 192.168.1.63 C. 192.168.1.70 D. 192.168.1.71
Virtual IP
244. A second router was installed on a network to be used as a backup for the primary router that works as a gateway. The infrastructure team does not want to change the IP address of the gateway on the devices. Which of the following network components should be used in this scenario? A. Loopback IP B. Virtual IP C. Reserved IP D. Public IP
Gateway: 192.168.1.97 Netmask: 255.255.255.224
257. A network technician needs to subnet the network. The marketing department has 28 devices. Which of the following private IP address spaces should be used to ensure the MINIMUM number of unused IP addresses? A. Gateway: 10.10.10.1 Netmask: 255.255.255.192 B. Gateway: 172.15.18.128 Netmask: 255.255.255.224 C. Gateway: 192.168.1.97 Netmask: 255.255.255.224 D. Gateway: 224.102.113.65 Netmask: 255.255.255.192
APIPA
261. Users on a LAN segment are reporting a loss of connectivity to network services. The client PCs have been assigned with 169.254.X.X IP addresses. Which of the following IP address schemas is being utilized? A. Private IP B. Static IP C. APIPA D. Loopback
164.10.12.128/26
278. A network administrator needs to implement a new IP subnet containing 29 hosts. It is possible that the number of hosts in that subnet could eventually double. The company only has a single, unused public IP network left to work with: 164.10.12.0/24. Which of the following would be the BEST way to divide this network without wasting addresses? A. 164.10.12.0/24 B. 164.10.12.64/29 C. 164.10.12.128/26 D. 164.10.12.191/28
DHCP scope exhaustion
28. After rebooting a PC, a user is no longer able to connect to the corporate network. As a test, the technician plugs a different laptop into the same network jack and receives an IP address of 169.254.112.137. Which of the following is MOST likely causing the issue? A. DHCP scope exhaustion B. Improper DNS setting C. Incorrect ACL setting D. Port-security violation
The technician is setting the default gateway.
298. A network technician does not have access to the GUI of a server and needs to adjust some network properties. Given the command: route add 0.0.0.0 mask 0.0.0.0 192.169.1.222 metric 1 Which of the following is the technician attempting to alter? A. The technician is clearing the route table. B. The technician is adding a static IP address. C. The technician is clearing the subnet mask setting. D. The technician is setting the default gateway.
Finance: 10.1.100.0/25 Human resources: 10.1.100.128/26 IT: 10.1.100.192/27
300. The corporate head office has assigned the subnet of 10.1.100.0/24 to a network technician. The technician wants to create subnets for the finance department, human resources, and IT. Given the following device counts: Finance: 70 devices - Human resources: 38 devices - IT: 16 devices - Which of the following outlines how the technician should allocate the address space given? A. Finance: 10.1.100.0/21 Human resources: 10.1.100.128/22 IT: 10.1.100.192/23 B. Finance: 10.1.100.0/23 Human resources: 10.1.100.128/22 IT: 10.1.100.192/21 C. Finance: 10.1.100.0/25 Human resources: 10.1.100.128/26 IT: 10.1.100.192/27 D. Finance: 10.1.100.0/26 Human resources: 10.1.100.128/27 IT: 10.1.100.192/28
VLSM
318. A network technician needs to create separate networks for several classrooms and administrative offices. They have been provided with the network address 192.168.1.0/24. They will need five classrooms of 25 hosts, two classrooms of 14 hosts, six admin hosts on the network, and three subnets for router connections. Which of the following IP concepts would need to be deployed? A. VLSM B. Class B private network C. EUI-64 D. IPv6
127.0.0.0/24 is the reserved loopback network and cannot be used for host networks.
350. A network administrator has configured the network on each floor of a four-story building to have the following different subnets: 10.0.10.0/24, 127.0.0.0/24, 172.16.0.0/24, and 192.168.255.0/24. After implementing these networks, the administrator realizes there has been a mistake. Which of the following BEST describes the mistake? A. 10.0.10.0/24 is not valid because 0 in the second octet cannot be used in the network portion of the IP address. B. 127.0.0.0/24 is the reserved loopback network and cannot be used for host networks. C. 172.16.0.0/24 is the reserved multicast network and cannot be used for host networks. D. 192.168.255.0/24 is not valid because 255 in the third octet cannot be used in the network portion of the IP address.
There is an incorrect default gateway on the user's PC.
365. A user in the finance department can access the department printer and file server yet is unable to print to the marketing department's printer. A technician runs ipconfig and sees the following output: IPv4 Address: 192.168.0.101 Subnet Mask: 255.255.255.0 Default Gateway: 192.168.1.1 The technician has verified the user's PC is in the proper VLAN and sees an UP/UP status on the switchport. Which of the following is MOST likely causing the issue? A. The user's IP is the broadcast address. B. The two printers share the same IP address. C. There is an incorrect default gateway on the user's PC. D. The ARP table on the switch has not been cleared.
APIPA
379. A technician set up a small network, which is not connected to the company LAN, for several employees to play a peer-to-peer networking game during breaks. The users know how to set up the software, but they do not know anything about networking. The technician has wired the network but has not configured any networking information and does not want the employees to have access outside the network. Which of the following should be used to apply addressing to the network? A. NAT B. VLSM C. APIPA D. CIDR
Pool
386. Which of the following DHCP settings defines the range of dynamic IP addresses? A. Exclusions B. Pool C. Reservations D. Scope options
DHCP reservation for the laptops' MACs
39. A user calls the help desk for assistance with setting up a new SOHO router. The user has three employees who all have laptops that need to connect to the wireless network. The users need to have firewall rules allowing access to an internal server, but cannot be configured with static IP addresses. Which of the following BEST describes what the technician should implement? A. CNAME record in the users' dynamic DNS accounts B. Additional lease time for the laptop computers C. IP helper relay system for configuration hops D. DHCP reservation for the laptops' MACs
255.255.255.192
392. A host has an IP address of 172.28.57.144 and is on the 172.28.57.128 subnet. Which of the following is a correct subnet mask of the host? A. 255.255.255.0 B. 255.255.255.192 C. 255.255.255.240 D. 255.255.255.248
Incorrect default gateway
4. A network technician receives a call from a user in the accounting department stating that Internet connectivity has been lost after receiving a new workstation. No other users in accounting are reporting similar issues. The network technician is able to ping the machine from the accounting department's router, but is not able to ping the machine from the IT network. Which of the following is MOST likely the cause? A. Incorrect default gateway B. Duplicate IP address C. Misconfigured OSPF D. Improper VLAN assignment
255.255.240.0
4. A technician is configuring a new server with an IP address of 10.35.113.47 on the 10.35.112.0 subnet to allow for the maximum number of hosts. When configuring network settings, which of the following is the correct subnet mask? A. 10.35.112.0/30 B. 10.35.112.0/24 C. 255.255.240.0 D. 255.255.248.0 E. 255.255.255.0
Cable modem
40. A home user is unable to get to the Internet from a workstation that is connected to a wireless network. When reviewing the results of the ipconfig command, the user wants to verity the default gateway is correct. Which of the following devices should be the gateway? A. Cable modem B. SOHO router C. DNS server D. Layer 2 switch
Loopback adapter
40. A technician is diagnosing an issue with a new T1 connection. The router is configured, the cable is connected, but the T1 is down. To verify the configuration of the router, which of the following tools should the technician use? A. Loopback adapter B. Cable tester C. Tone generator D. Multimeter
Bad switchport
404. A new employee is unable to access any network resources. All other users are able to access the network at 100Mbps. No IP address, subnet mask, or default gateway is displayed on the new employee's workstation. The network administrator reterminates all connectors using the correct standard. Upon further investigation, the network administrator also notices the following: Wire map results from the user patch cable to the patch cable connecting to the switch: ✑ Pins 5 and 7 are short. ✑ The distance is 200ft (61m). Additional observations on the switch: ✑ The VLAN is set correctly. ✑ The port is not disabled. ✑ The duplex/speed settings are correct. ✑ Port LEDs are off for that port. ✑ The port is set to untagged. Which of the following is the MOST likely reason the new employee is having network issues? A. Bad switchport B. Incorrect pinout C. Open/short D. VLAN mismatch E. Distance limitation
Rouge DHCP server
41. A network technician receives a call from a user who is experiencing network connectivity issues. The network technician questions the user and learns the user brought in a personal wired router to use multiple computers and connect to the network. Which of the following has the user MOST likely introduced to the network? A. Rogue DHCP server B. Evil twin C. VLAN mismatch D. Honeypot
DHCP snooping
424. Employees at a company report that they are unable to access the Internet. A network technician notices the workstations are receiving IP addresses that do not follow the IP addressing scheme of the corporate network. Upon further inspection, the technician finds an employee has plugged a rogue wireless router into the corporate network. Which of the following settings would have prevented this situation? A. DHCP snooping B. DHCP relay C. DHCP leasing D. DHCP options
10.8.0.0/16
47. Based on networks 10.8.16.0/22 and 10.8.31.0/21, which of the following is the BEST summarized CIDR notation? A. 10.8.0.0/16 B. 10.8.0.0/19 C. 10.8.0.0/20 D. 10.0.0.0/24
DHCP reservation
74. An end-user device requires a specific IP address every time it connects to the corporate network; however, corporate policy does not allow the use of static IP addresses. Which of the following will allow the request to be fulfilled without breaking the corporate policy? A. DHCP relay B. DHCP exclusion C. DHCP option D. DHCP reservation
Use a loopback at the demark and router, and check for a link light
85. A telecommunications provider has just deployed a new OC-12 circuit at a customer site. While the circuit showed no errors from the provider end to the customer's demarcation point, a network administrator is trying to determine the cause of dropped packets and errors on the circuit. Which of the following should the network administrator do to rule out any problems at Layer 1? (Choose two.) A. Use a loopback at the demark and router, and check for a link light B. Use an OTDR to validate the cable integrity C. Use a pinout tester to validate the cable integrity D. Use a multimeter to validate the cable integrity E. Check for any devices that may be causing EMI on the cable F. Clean the cables to be sure they are free of dust and debris