hard-questions.txt

HARD QUESTIONS - NETWORK+

These are questions that I missed in MeasureUp or the book that I should work on.

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3) What component performs signal amplification to extend the maximum
   allowable distance for a media type?

Repeater


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11) How is the decimal value 171 expressed in hex?

0xAB

  -> Divide 171 by 16 until QUOTIENT is zero.
     171 / 16 = 10%11
     10 / 16 = 0%10
  -> 10 = A
     11 = B
  -> 0xAB

In binary - 10101011


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13) Which grade or grades of fiber have a 62.5 micron core?

MMF(OM1,OM2)


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14) Which fiber Ethernet standard is best suited to implementing backbone
    cabling that does not exceed 200 m (656 feet) and can achieve at least
    4 Gbps throughput?

10GBASE-SR MMF(OM1,OM2)


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22) You have selected an SFP+ 1310 nm Tx and 1490 nm Rx transceiver to
    implement a BiDi link between two switches. Should you provision a
    second SFP+ 1310 nm Tx and 1490 nm Rx for the other switch?

No, we need an SFP+ module with 1490nm Tx and 1310nm Rx.


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18) A network technician needs a cost-effective solution that can multiplex
    up to 16 wavelengths on an SFP/SFP+ interface. Which multiplexing
    technique should the network technician use?

CWDM supports up to 16 wavelengths and typically deploys 4 or 8 bidirectional
channels over a single fiber strand.


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1) You need to verify whether a switch port is misconfigured by checking
the number of collisions being reported. What general command could
you use at a CLI to report this information?

# sh interface


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4) A network engineer is setting up MTU sizes to follow most Ether products.
In normal conditions, what is the maximum size of a standard Ethernet frame,
excluding the preamble?

1518bytes


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8) A network architect is assessing network performance. Which of the following
is part of the CSMA/CD protocol to identify collisions early?

Preamble
SFD


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11) A network technician is setting up a connection between switches, but
the switches cannot establish a connection. Which of the following would be
the most likely cause of the switch's inability to establish a connection?

Dual MDI-X ports


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A network admin implements a change on a switch to fix a network issue.
What should the admin do next?

Implement preventative measures.


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A company wants to implement authentication and authorization solution for
network devices that also directly supports device management.

TACACS+

(RADIUS doesn't support device management)


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An admin wants to deploy new wlan topology without running new wiring.
Must support 5Ghz, MU-MIMO, speeds of 2100Mbps, PoE 25W+.
What two components must be used?

An AP supporting 802.11ax Wave 2 (5Ghz, MU-MIMO, 2Gbps+).
A switch supporting 802.3at (PoE).


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The connection between an access and distribution switch is over utilized.
Which should a network engineer use to increase bandwidth between the switches?

Link Aggregation Control Protocol(LACP)

Can be used to increase bandwidth between switches. LACP aggregates two or more
Ethernet interfaces, allowing the interfaces to operate on a single virtual
interface. LACP must be configured on both switches and the same number of ports
must be added to the LACP channel on both ends.


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DHCP - Application
SMTP - Application
ICMP - Network
TCP - Transport
DNS - Application
FTP - Application


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A vulnerability is a flaw or weakness in security that could lead to a security
breach.

An exploit is an attack that takes advantage of a vulnerability.


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VLAN hopping is an attack in which the attackers computer gains access to a
port that would normally not be accessible to that computer. A way to carry
out this attack is by double tagging frames with the attack switch and the
target switch, making it look like the frame was intended for the target
switch.


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SNMP can collect performance and event information from network devices and
configure SNMP agents on nodes allowing for device config modification.


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An admin suspects a WAP antenna needs to be replaced. Which antenna type
should be used to maximize gain?

A parabolic dish antenna. Like a satellite dish, heavily focusing RF energy in
a tight beam (i.e. maximizing gain).


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If an AP has over 50 clients, a general rule of thumb is that more APs need to
be added.


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MFA must have one or more differing factors:
  -> Something you know
  -> Something you have
  -> Something you are
  -> Something you do
  -> Somewhere you are


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VNC is platform independent, RDP is Windows proprietary


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A company wants to connect a remote office using a satellite internet service.
What is the main concern for this deployment?

Latency, which is described as the amount of delay that occurs during a data
transmission.


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An admin is concerned about the security of east-west traffic flows.
Whhat is best to address these concerns?

Place firewalls between datacenter segments. East-west traffic flow is the flow of
traffic between endpoints within the same datacenter.


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An ISP has installed a DWDM device. Why?

To solve the fiber exhaust problem.


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Network Masks
A 32-bit network mask is what distinguishes the Network ID from the Host ID.

The mask conceals the host ID portion and leaves the network portion revealed.
Wherever there is a binary one in the netmask, it corresponds with the net ID.

This is a process called ANDing. We are ANDing the mask to the IP address,
because when two 1s are ANDed together the result is 1. Any other combo
returns a 0.

Let's determine the network ID:

1) First AND the two addresses to binary
198.51.100.1    =    11000110 00110011 01100100 00000001
                                  AND
255.255.255.0   =    11111111 11111111 11111111 00000000
                                   =
198.51.100.0    =    11000110 00110011 01100100 00000000


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What is the lowest ANSI/TIA/EIA copper Ethernet cabling category available in the
form of shielded/foiled twisted pair (S/FTP), and is often recommended for use in
healthcare settings?

6a fully shielded cabling has a braided outer screen and foil-shielded pairs.


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A Windows server manager is trying to calculate the amount of data loss that a
system can sustain, measured in time units. What is this referred to as?

Recovery Point Objective (RPO) is the amount of data loss that a system can
sustain, measured in time units.


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A network security practitioner is hardening a corporate network to mitigate the
risk from route processor vulnerabilities. Which quality of service (QoS) stack
operational layer comprises traffic that keeps the network itself operational,
including routing updates, ARP traffic, STP notifications, NTP updates, QoS
classification, and link reservation requests?

Control plane


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Set roaming aggressiveness in an isolated setting: Low
Set rooaming aggressiveness in a mixed setting: Medium

If a company is using a wireless distribution, all repeaters must be on the same
channel.


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A team of network engineers are refurbishing copper Ethernet cabling in a FEMA
office. The federal government requires that copper twisted pair cabling be
terminated according to the T568A standard. To ensure termination is being done
according to standard, what color conductor will be wired to the second pin?

Green

T568A -> wire 2 = green
T568B -> wire 6 = green


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A network engineer is configuring a local intranet for a large manufacturing
company that uses a DNS server on its network to resolve internal and external
queries while keeping internal IP addresses private. The engineer sets both UDP
port 53 and TCP port 53 on the primary name resolution server to allow larger DNS
record transfers. Select the situations that would require larger DNS record
transfers over TCP. (Select all that apply.)

The DNS server is utilizing a security protocol such as DNSSEC.
The network deploys IPv6 addressing.


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A network engineer is planning static routes through an IPv6-enabled network. The
engineer has configured the network so that each device or interface is
represented by a 64 bit Interface ID. Which section of how many bits of an IPv6
address can the Interface ID be found?

The last 64-bits


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A service provider has terminated a T1 link to a mid-sized company using the
T-carrier system. After patching from where the service provider terminated their
connection, where would the customer connect for connectivity?

DSU. The customer connects to the CSU/DSU


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A network consultant has just arrived on-premises to address a support ticket
regarding several users being unable to log in. Decide which of the following
courses of action the consultant should take first.

Question users


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A network technician is manually configuring speed and duplex settings in a
managed switch, in order to define specific speeds for specific devices. After
testing the manual configuration of a single test device, the technician notes
that the LED indicator corresponding to the port the test device is connected to
is blinking amber. Recommend a next step for the technician to investigate.

Check duplex settings


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How does the TCP/IP protocol suite resolve the machine hardware address of the
target IP if the target IP is on a remote network?

Determines the MAC of the default gateway using the ARP cache.


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A network engineer is testing an application over the IPv6 protocol. Determine
how the server can cast packets to an entire local subnet.

Multicast to associated private topology or MLD.


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A team of network engineers is using an interior gateway routing protocol that
takes into consideration only the number of hops when calculating routes.
Recommend an interior gateway routing protocol that calculates routes using a
metric weighted on bandwidth cost combined with delay time, and that only sends
updates to neighbors when the topology has changed.

EIGRP


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A systems administrator is configuring a server for email services. Which protocol or protocol command is also referred to as implicit TLS?

SMTPS


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A network cabling installer is installing cable in a senior care center. A distance of about 80 meters (262 feet) must be connected with a single copper twisted-pair Ethernet cable. What is the minimum acceptable class of cable for covering the distance at 10GBASE-T without repeaters?

Cat 6a


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A network engineer is troubleshooting a packet loss issue on a small corporate
Internet of Things (IoT) network. The issue began occurring after a legacy device
was added to the network, and the engineer has noted that the MTU size on the
router is less than the default 1500, at 750 MTU. Propose a likely cause of the
packet loss by the legacy device.

The legacy device does not support fragmentation


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A network engineer is configuring an Internet of Things (IoT) network that uses
multicasting to allow devices to communicate over a VLAN-enabled managed switch.
An issue is occurring where the multicast traffic is being flooded across the
network as a broadcast, resulting in reduced network performance. Recommend a
potential fix for this issue.

Ensure IGMP snooping is enabled at the switch.


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A network specialist is installing a VoIP gateway in an office building that uses
a legacy analog phone system. The office managers want to be able to use the old
phone handsets and fax machines as well as add new VoIP endpoints but plans to
cancel services with the company providing the analog telephone services and
replace all legacy voice cabling. Plan a method for providing VoIP services while
retaining legacy handsets and fax machines. (Select all that apply.)

Install a VoIP PBX between the VoIP service provider and VoIP endpoints, and a
Foreign Exchange Subscriber (FXS) voice gateway connecting legacy hardware to the
new PBX.

Connect new devices to the VoIP PBX and connect that to the legacy telephone
network directly through an analog Foreign Exchange Office voice gateway.

There is no legacy PBX.


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A corporate network is configured with authentication based on digitally signed
certificates issued by an approved certificate authority. Select the type of
authentication being used.

Public Key Infrastructure (PKI). PKIs use CAs to issue certs containing keys.


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A manufacturing company utilizes multiple access points (APs) spread across its
factory. The APs all share an SSID to allow client roaming. Since there are areas
where it is difficult to run cabling, a wireless distribution system is used,
where the main router is connected to the Internet and the rest are set in
repeater mode. What is true about the channels used by the APs?

APs should avoid using channels that overlap.


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A systems administrator is trying to distribute client requests across server
nodes in a farm or pool based on application-level data, such as a request for a
particular URL. Which of the following should they set up?

Contect switch. This is a layer 7 load balancing switch.


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A security analyst is looking at attacks against unencrypted Neighbor Discovery
(ND) protocol. What is the attacker most likely trying to accomplish?

Layer 2 spoofing. ND is an IPv6 technology, IPv6 doesn't use ARP.


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A small organization is looking at cloud solutions, but does not possess the
\necessary number of servers to conduct operations or the appropriate number of
employees to complete tasks. To support their mission, the organization attempts
to provide incentives, such as working from home by using virtual desktops as a
means to attract applicants and fulfill computing requirements without owning the
required amount of servers. Which cloud model would probably suit the
organization best?

DaaS; Desktop as a Service


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A security auditor for a major company is performing a compliance audit in
accordance with their companies' policy. They are currently assessing the
likelihood and impact (or consequence) of a threat actor exercising a
vulnerability. What is this referred to as?

Risk


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A network administrator is with a major company that cannot handle downtime and
requires redundancy at every level possible. They need to set up multiple
physical routers to serve as a single default gateway for a subnet, but do not
want to use a proprietary protocol. Which of the following will help them
accomplish this? (Select all that apply.)

CARP; enables multiple hosts to chare an IP on the same network segment so they
can act as a default gateway.

VRRP; allows the automatic assignment of IP routers to act as a default gateway
on a single subnet.


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While performing a resiliency test for availability, a technician is trying to
calculate the amount of data loss that a system can sustain, and further
calculate the time it would take for a database to be recovered if it was
targeted by a virus. What is the technician testing for?

RPO. Recovery point objective is the amount of data loss that a system can
sustain.


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MTTR = (total repair time / number of incidents)

MTBF = (devices * hrs) / (number of failures)

MTTF = (devices * hrs) / (number of devices)


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Encryption protocol: DTLS (
Device GW msg protocol: CoAP (works over UDP with DTLS)
Enable QoS for msgt port: 5684
Monitoring and management protocol: SNMP
Link aggregation with redundant cabling: YES (to ensure heartbeats pass correctly)
Preferred layer 4 protocol: UDP (lightweight, connectionless)
private IP suubnets --- i.e. 192.168.1.0/24 && 192.168.2.0/24
Use managed layyer 3 switch: YES
Use load balancing: YES (used w/ link aggregation for heartbeat fault-tolerance)
Use Spanning Tree: YES
Use Power Savin Mode (PSM): NO (to ensure IoT devices remain active)
Heartbeat Interval: 2sec (because it is less than the Keepalive value)
Segregate from Main Network: YES
Use Static Routing and Addressing: YES