Interconnecting Cisco Networking Devices Part 1 (ICND1) 100-105 — Questions and Answers

Question 1: Which command verifies that SSH version 2 is configured on a Cisco device?

show ssh version
show crypto ssh
show ip ssh (Correct answer)
show service ssh

Correct answer: show ip ssh

The 'show ip ssh' command displays the SSH version, authentication timeout, and retry settings configured on the Cisco device.

Question 2: How does the ICND1 body of knowledge relate to daily professional practice?

It only applies during certification exams
It is theoretical and has limited practical application
It is relevant only for academic research
It provides the foundational framework that guides decision-making and standard practices (Correct answer)

Correct answer: It provides the foundational framework that guides decision-making and standard practices

The body of knowledge provides the foundational framework of principles, standards, and best practices that professionals use to guide their daily decision-making, ensure consistent quality, and maintain alignment with industry standards.

Question 3: Which protocol is used to map an IP address to a MAC address on a local network?

DNS
RARP
ARP (Correct answer)
DHCP

Correct answer: ARP

ARP (Address Resolution Protocol) is a crucial protocol used on local networks to map an IP address to its corresponding MAC (Media Access Control) address. When a device needs to communicate with another device on the same segment, it uses ARP to discover the physical MAC address associated with the destination's logical IP address.

Question 4: A packet destined for 192.168.1.255 on a /24 network is sent as what type of transmission?

Multicast
Directed broadcast (Correct answer)
Unicast
Limited broadcast

Correct answer: Directed broadcast

192.168.1.255 is the directed (subnet) broadcast for 192.168.1.0/24, sent to all hosts on that subnet.

Question 5: Which feature prevents routing loops in distance-vector protocols by not advertising a route back out the interface from which it was learned?

Split horizon (Correct answer)
Route poisoning
Triggered updates
Hold-down timer

Correct answer: Split horizon

Split horizon prevents routing loops by prohibiting a router from advertising a route back on the same interface it was received from.

Question 6: Which command displays the current NTP synchronization status and stratum of a Cisco router?

show ntp associations
show clock detail
debug ntp all
show ntp status (Correct answer)

Correct answer: show ntp status

'show ntp status' displays the current NTP synchronization state, stratum level, reference server, and clock offset.

Question 7: What Cisco IOS command sends Syslog messages to a remote server at 10.0.0.5?

debug logging 10.0.0.5
logging trap 10.0.0.5
snmp-server host 10.0.0.5
logging host 10.0.0.5 (Correct answer)

Correct answer: logging host 10.0.0.5

The 'logging host' command directs syslog output to the specified remote syslog server IP address.

Question 8: Which type of IPv6 address is used to identify a set of interfaces, delivering the packet to the nearest one?

Unicast
Broadcast
Multicast
Anycast (Correct answer)

Correct answer: Anycast

Anycast addresses are assigned to multiple interfaces; routing delivers packets to the topologically nearest interface in that set.

Question 9: In ICND1 practice, what is the best approach to quality improvement in subnetting?

Wait for problems to occur before acting
Use data-driven methods with measurable outcomes (Correct answer)
Make changes without measuring results
Copy what other organizations do without analysis

Correct answer: Use data-driven methods with measurable outcomes

Data-driven quality improvement with measurable outcomes ensures that changes actually produce the intended improvements and can be verified.

Question 10: What does the 'show cdp neighbors' command display?

Routing table entries for directly connected networks
MAC address table of connected switches
OSPF neighbor adjacency states
Directly connected Cisco devices and their interface information (Correct answer)

Correct answer: Directly connected Cisco devices and their interface information

CDP (Cisco Discovery Protocol) neighbors shows directly connected Cisco devices, their platform, capabilities, and connected interface.

Question 11: In STP, which port state actively forwards user traffic and learns MAC addresses?

Forwarding (Correct answer)
Blocking
Listening
Learning

Correct answer: Forwarding

Only the Forwarding state allows a port to send and receive data traffic; it is the final stable active state.

Question 12: A host has IP 172.16.45.200/20. What is the network address of this subnet?

172.16.40.0 (Correct answer)
172.16.32.0
172.16.48.0
172.16.45.0

Correct answer: 172.16.40.0

A /20 has a block size of 16 in the third octet; 32 ≤ 45 < 48, so the network is 172.16.40.0.

Question 13: When assessment results for a Interconnecting Cisco Networking Devices Part 1 evaluation are inconclusive, the BEST practice is to:

Conduct additional assessment using alternative methods (Correct answer)
Delay reporting until results are favorable
Discard the results and start over completely
Report the results as definitive anyway

Correct answer: Conduct additional assessment using alternative methods

Inconclusive results require additional assessment using alternative methods to gather more data. This triangulation approach helps clarify findings without compromising the integrity of the assessment process.

Question 14: What does the 'network 10.0.0.0 0.255.255.255 area 0' command do under the OSPF process?

Enables OSPF on all interfaces with IPs matching the 10.x.x.x range and places them in area 0 (Correct answer)
Summarizes the 10.0.0.0/8 network for area 0
Blocks OSPF on interfaces outside the 10.0.0.0 range
Adds a static route for 10.0.0.0/8 in area 0

Correct answer: Enables OSPF on all interfaces with IPs matching the 10.x.x.x range and places them in area 0

The 'network' command with a wildcard mask enables OSPF on matching interfaces and assigns them to the specified area.

Question 15: Which of the following is the correct range for a Class C private IP address?

192.168.0.0 - 192.168.255.255 (Correct answer)
172.16.0.0 - 172.31.255.255
198.51.100.0 - 198.51.100.255
10.0.0.0 - 10.255.255.255

Correct answer: 192.168.0.0 - 192.168.255.255

The Internet Assigned Numbers Authority (IANA) reserves specific IP address ranges for private use within local networks. For Class C networks, the designated private range is 192.168.0.0 through 192.168.255.255, commonly utilized in residential and small business network setups.

Question 16: Which security protocol provides integrity, authentication, and optional encryption for IP packets at Layer 3?

802.1X
IPsec (Correct answer)
SSL/TLS
RADIUS

Correct answer: IPsec

IPsec is a suite of protocols that operates at Layer 3 to provide authentication, integrity verification, and optional encryption for IP communications.

Question 17: What is the purpose of the 'area 0' designation in OSPF?

It is the backbone area that all other areas must connect to (Correct answer)
It limits OSPF to a single router
It is a reserved area for loopback interfaces
It is a stub area that blocks external routes

Correct answer: It is the backbone area that all other areas must connect to

Area 0 is the OSPF backbone area, and all other areas must connect to it either directly or via a virtual link.

Question 18: What is the PRIMARY purpose of obtaining ICND1 certification in Interconnecting Cisco Networking Devices Part 1?

To bypass educational requirements
To guarantee employment in the field
To satisfy a personal achievement goal
To demonstrate verified competency and adherence to professional standards (Correct answer)

Correct answer: To demonstrate verified competency and adherence to professional standards

Professional certification demonstrates that an individual has met established competency standards through verified assessment. It provides assurance to employers, clients, and the public that the certified professional possesses the knowledge and skills required for competent practice.

Question 19: What is the best practice for maintaining infrastructure maintenance performance over time?

Wait for failures before acting
Outsource all maintenance
Implement scheduled preventive maintenance (Correct answer)
Upgrade all equipment annually

Correct answer: Implement scheduled preventive maintenance

Scheduled preventive maintenance catches potential issues before they cause failures, maintaining reliability and extending equipment life.

Question 20: A Cisco switch needs to be configured with a management IP address. On which interface is this typically configured?

FastEthernet0/0
Console 0
Vlan1 (SVI) (Correct answer)
GigabitEthernet0/1

Correct answer: Vlan1 (SVI)

A Layer 2 switch uses a Switched Virtual Interface (SVI), typically VLAN 1, to assign a management IP address.

Question 21: Which statement correctly describes OSPF route summarization at an Area Border Router (ABR)?

The 'area range' command is used on ABRs to summarize routes between areas (Correct answer)
Summarization is automatic between all OSPF areas
The 'summary-address' command is used on ABRs for inter-area summarization
OSPF does not support route summarization

Correct answer: The 'area range' command is used on ABRs to summarize routes between areas

The 'area range' command on an ABR aggregates Type 3 LSAs sent between areas, reducing LSDB size.

Question 22: Which protocol and port does SNMP use for NMS-to-agent queries?

UDP port 161 (Correct answer)
TCP port 161
UDP port 162
TCP port 162

Correct answer: UDP port 161

SNMP uses UDP port 161 for NMS-to-agent queries (Get/Set), while traps and informs use UDP port 162.

Question 23: In Interconnecting Cisco Networking Devices Part 1, what is the PRIMARY purpose of conducting an initial assessment?

To fulfill administrative paperwork requirements
To generate documentation for billing purposes
To establish a baseline and identify needs for appropriate action (Correct answer)
To demonstrate the assessor's expertise

Correct answer: To establish a baseline and identify needs for appropriate action

The initial assessment establishes a baseline of current conditions and identifies specific needs. This foundational information guides all subsequent decisions, planning, and interventions.

Question 24: Which statement BEST describes the relationship between Interconnecting Cisco Networking Devices Part 1 certification requirements and industry evolution?

Certification requirements never change once established
Requirements evolve periodically to reflect advances in knowledge, technology, and practice standards (Correct answer)
Requirements become less stringent over time
Changes only occur when government mandates new requirements

Correct answer: Requirements evolve periodically to reflect advances in knowledge, technology, and practice standards

Certification requirements evolve to keep pace with advances in professional knowledge, technological developments, and changes in practice standards. This ensures that certified professionals remain current and competent in a changing professional landscape.

Question 25: What does the EIGRP term 'feasible successor' refer to?

A route with equal cost to the successor
A backup route that meets the feasibility condition (Correct answer)
The route currently in the routing table
The router that originates a route

Correct answer: A backup route that meets the feasibility condition

A feasible successor is a backup path whose reported distance is less than the successor's feasible distance, stored in the topology table.

Question 26: Which approach best demonstrates mastery of ipv4 and ipv6 in ICND1 practice?

Avoiding complex scenarios
Following procedures without understanding
Relying entirely on technology
Applying principles to novel situations with sound judgment (Correct answer)

Correct answer: Applying principles to novel situations with sound judgment

True mastery involves understanding underlying principles well enough to apply them to new and unfamiliar situations with professional judgment.

Question 27: Which attack technique allows a host to send frames on a VLAN it should not access by exploiting trunk negotiation?

ARP poisoning
STP root takeover
VLAN hopping via double tagging (Correct answer)
MAC flooding

Correct answer: VLAN hopping via double tagging

Double-tagging attacks embed an inner VLAN tag that gets processed after the outer tag is stripped at the first trunk.

Question 28: Which OSPF packet type is used to discover and maintain neighbor relationships?

LSU
Hello (Correct answer)
LSR
DBD

Correct answer: Hello

OSPF Hello packets are sent periodically to discover neighbors and verify adjacency is maintained.

Question 29: Which foundational principle is MOST important for success in the Interconnecting Cisco Networking Devices Part 1 profession?

Commitment to continuous learning, ethical practice, and quality outcomes (Correct answer)
Maintaining the minimum requirements for certification
Maximizing financial returns on every engagement
Specializing in only one narrow area of practice

Correct answer: Commitment to continuous learning, ethical practice, and quality outcomes

Success in any professional field requires a commitment to continuous learning to stay current, ethical practice to maintain trust and integrity, and a focus on quality outcomes that serve stakeholders and the public interest.

Question 30: An administrator wants to limit Syslog messages to only warnings and above. Which command accomplishes this?

logging trap warnings (Correct answer)
logging trap informational
logging trap debug
logging trap emergencies

Correct answer: logging trap warnings

The 'logging trap warnings' command sets the minimum severity level to 4 (Warning), sending levels 0-4 to the Syslog server.

Question 31: What is the broadcast address of the subnet 192.168.10.64/26?

192.168.10.191
192.168.10.128
192.168.10.126
192.168.10.127 (Correct answer)

Correct answer: 192.168.10.127

A /26 block size is 64; subnet 192.168.10.64 has broadcast at .127 (64+64-1).

Question 32: Which assessment method provides the MOST reliable data for ICND1 professionals making critical decisions?

Social media reviews and testimonials
Single-source data from one stakeholder
Standardized tools combined with professional observation (Correct answer)
Informal verbal feedback alone

Correct answer: Standardized tools combined with professional observation

Combining standardized assessment tools with professional observation provides the most reliable and comprehensive data. Standardized tools ensure consistency and validity, while professional observation captures nuances that tools might miss.

Question 33: Which protocol is used to determine the best path for data to travel in a network?

ARP
DNS
DHCP
OSPF and RIP (Correct answer)

Correct answer: OSPF and RIP

OSPF (Open Shortest Path First) and RIP (Routing Information Protocol) are both routing protocols used by routers to determine the most efficient path for data packets to travel across a network. They achieve this by exchanging routing information with other routers and calculating the best routes based on various metrics, such as hop count or link cost. These protocols are essential for efficient data delivery in complex networks.

Question 34: Which OSPF network type is assigned by default on a Cisco Ethernet interface?

Non-broadcast
Point-to-multipoint
Broadcast (Correct answer)
Point-to-point

Correct answer: Broadcast

Ethernet interfaces default to the OSPF broadcast network type, which elects a DR and BDR.

Question 35: An administrator issues 'switchport trunk allowed vlan 10,20,30' on a trunk interface. What is the effect?

Only VLANs 10, 20, and 30 are allowed; all others are pruned (Correct answer)
VLANs 10, 20, and 30 are added to the existing allowed list
The native VLAN is changed to VLAN 10
VLANs 10, 20, and 30 are removed from the trunk

Correct answer: Only VLANs 10, 20, and 30 are allowed; all others are pruned

Using 'switchport trunk allowed vlan' (without 'add') replaces the entire allowed list with only the specified VLANs.

Question 36: Which professional attribute is most valued in ospf configuration within the ICND1 field?

Avoiding challenging situations
Accountability and commitment to standards (Correct answer)
Prioritizing personal convenience
Working in isolation

Correct answer: Accountability and commitment to standards

Accountability and commitment to professional standards build trust and ensure consistent, high-quality practice.

Question 37: Which IEEE standard defines Rapid Spanning Tree Protocol (RSTP)?

IEEE 802.1W (Correct answer)
IEEE 802.1D
IEEE 802.1S
IEEE 802.1Q

Correct answer: IEEE 802.1W

IEEE 802.1W defines RSTP, which was later incorporated into the revised 802.1D-2004 standard for faster convergence.

Question 38: Which statement BEST describes the relationship between Interconnecting Cisco Networking Devices Part 1 certification requirements and industry evolution?

Changes only occur when government mandates new requirements
Requirements evolve periodically to reflect advances in knowledge, technology, and practice standards (Correct answer)
Certification requirements never change once established
Requirements become less stringent over time

Correct answer: Requirements evolve periodically to reflect advances in knowledge, technology, and practice standards

Question 39: What distinguishes a Interconnecting Cisco Networking Devices Part 1 certified professional from a non-certified practitioner?

Certified professionals always have more years of experience
There is no meaningful difference in competency
Certification validates competency through standardized assessment against established benchmarks (Correct answer)
Certified professionals exclusively work in larger organizations

Correct answer: Certification validates competency through standardized assessment against established benchmarks

Certification provides objective validation of competency through standardized assessment. While non-certified practitioners may be skilled, certification offers verified evidence that a professional meets established benchmarks for knowledge and performance.

Question 40: A Cisco router has the following routes: S 10.0.0.0/8, O 10.1.0.0/16, and C 10.1.1.0/24. Which route is selected for a packet destined to 10.1.1.50?

O 10.1.0.0/16 because OSPF has a lower AD than static
O 10.1.0.0/16 because it has the longest match among dynamic routes
S 10.0.0.0/8 because static routes are preferred
C 10.1.1.0/24 because it is the longest prefix match (Correct answer)

Correct answer: C 10.1.1.0/24 because it is the longest prefix match

Longest prefix match is always the primary selection criterion; 10.1.1.0/24 is the most specific match for 10.1.1.50.

Question 41: What is the purpose of the OSPF dead interval?

The time after which a neighbor is declared down if no Hello is received (Correct answer)
The interval between LSA flooding cycles
The time OSPF waits before electing a new DR
The timeout for database exchange between neighbors

Correct answer: The time after which a neighbor is declared down if no Hello is received

If a router does not receive a Hello from a neighbor within the dead interval, it declares that neighbor down and recalculates routes.

Question 42: What is the function of the configuration register value 0x2142 on a Cisco router?

Bypasses the startup configuration in NVRAM (Correct answer)
Forces a full factory reset
Boots normally from flash
Enables ROM Monitor mode

Correct answer: Bypasses the startup configuration in NVRAM

Config register 0x2142 tells the router to ignore the startup-config, which is used for password recovery procedures.

Question 43: What is the MOST important factor to consider when selecting assessment tools for ICND1 certification work?

Personal familiarity with the tool
The cost of the assessment tool
How quickly the tool can be administered
Validity, reliability, and appropriateness for the specific context (Correct answer)

Correct answer: Validity, reliability, and appropriateness for the specific context

Assessment tools must be valid (measuring what they claim to measure), reliable (producing consistent results), and appropriate for the specific context and population. These psychometric properties ensure the quality of assessment outcomes.

Question 44: How many usable host addresses are available in a /27 subnet?

62
32
30 (Correct answer)
14

Correct answer: 30

A /27 subnet has 32 total addresses (2^5), minus 2 for network and broadcast, leaving 30 usable hosts.

Question 45: A network administrator wants to prevent a rogue switch from becoming a VTP server. Which action should be taken?

Set all switches to VTP client mode
Disable VTP pruning
Configure a VTP domain name of NONE
Set all switches to VTP transparent mode (Correct answer)

Correct answer: Set all switches to VTP transparent mode

VTP transparent mode switches do not participate in VTP synchronization, so a rogue switch in transparent mode cannot update the VLAN database.

Question 46: Which IEEE standard defines the original Spanning Tree Protocol?

IEEE 802.1Q
IEEE 802.1D (Correct answer)
IEEE 802.3
IEEE 802.1W

Correct answer: IEEE 802.1D

IEEE 802.1D defines the original STP specification; 802.1W defines RSTP and 802.1Q defines VLANs.

Question 47: In OSPF, which router is elected as the Designated Router (DR) on a multi-access segment?

The router with the lowest IP address
The router with the most routes in its routing table
The router with the highest router-ID and priority greater than 0 (Correct answer)
The first router to boot on the segment

Correct answer: The router with the highest router-ID and priority greater than 0

The DR is elected based on the highest OSPF priority, with the router-ID as a tiebreaker; a priority of 0 disqualifies a router.

Question 48: What does it mean when a neighbor shows 'FULL/DR' in the 'show ip ospf neighbor' output?

The adjacency failed and the router is the DR
The neighbor's LSDB is full and it acts as DR
The neighbor is a fully meshed DR-only router
The neighbor is fully adjacent and is the Designated Router (Correct answer)

Correct answer: The neighbor is fully adjacent and is the Designated Router

FULL/DR means the router has reached full adjacency with that neighbor, which is the Designated Router on the segment.

Question 49: What is the PRIMARY purpose of obtaining ICND1 certification in Interconnecting Cisco Networking Devices Part 1?

To satisfy a personal achievement goal
To demonstrate verified competency and adherence to professional standards (Correct answer)
To guarantee employment in the field
To bypass educational requirements

Correct answer: To demonstrate verified competency and adherence to professional standards

Question 50: What does the IPv6 prefix FF02::1 represent?

Solicited-node multicast
All routers on the local link
All nodes on the local link (Correct answer)
Loopback address

Correct answer: All nodes on the local link

FF02::1 is the all-nodes multicast address used to reach every IPv6-enabled device on the local link.

Interconnecting Cisco Networking Devices Part 1 (ICND1) 100-105

The ICND1 (100-105) exam, associated with the Cisco CCENT certification, tests foundational knowledge of network fundamentals, LAN switching, routing, infrastructure services, and infrastructure maintenance. The exam has been retired by Cisco and replaced by the consolidated CCNA 200-301.

Questions

90 min

Time Limit

83%

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