CCNA-CISCO Certified Network Associate Exam Testbank |All
Questions And Answers 2026/2027 | Verified Answers Plus
Rationales | Graded Q&A Comprehensive Study Guide |
Verified Latest 2027
1. A network engineer is configuring a new enterprise switch and needs to ensure that
unauthorized switches cannot form trunk links and inject rogue VLAN traffic into the
network. Which protocol should be disabled or configured securely on all user-facing
access ports to mitigate this vulnerability?
A. Spanning Tree Protocol
B. Dynamic Trunking Protocol
C. Link Layer Discovery Protocol
D. Virtual Router Redundancy Protocol
Dynamic Trunking Protocol (DTP) negotiates trunking automatically between Cisco switches.
Leaving access ports in dynamic auto or dynamic desirable modes allows an attacker to plug
in a rogue switch and form a trunk, gaining access to all VLANs. Disabling DTP or setting ports
to static access mode prevents this.
2. An administrator is troubleshooting an IPv6 connectivity issue on a Linux host and
notices that the node is unable to discover neighboring routers on the local link. Which
ICMPv6 message type is specifically utilized by Neighbor Discovery Protocol (NDP) for
router discovery?
A. Type 133
B. Type 135
C. Type 137
D. Type 130
ICMPv6 Type 133 corresponds to Router Solicitation (RS) messages, which hosts send to
discover routers on the link. Type 135 is Neighbor Solicitation, Type 137 is a Redirect Message,
and Type 130 is a Multicast Listener Query.
3. A junior administrator applies an access control list (ACL) to an interface but
mistakenly places an inbound standard ACL on the external interface facing the internet,
,inadvertently blocking internal users from reaching local corporate servers. Where should
standard ACLs ideally be placed in relation to the destination?
A. As close to the source as possible
B. As close to the destination as possible
C. In the middle of the network path
D. On the core distribution layer only
Standard ACLs filter traffic based solely on the source IP address. Because they do not inspect
destination addresses, placing them too close to the source can block unintended traffic
streams. They should always be placed as close to the destination as possible to avoid
collateral routing disruption.
4. A network technician needs to connect two modern Cisco switches using a standard
copper patch cable without crossover wiring. Which feature automatically detects the
signal pairs and configures the interface regardless of the cable type used?
A. Port Aggregation Protocol
B. Link Aggregation Control Protocol
C. Auto-MDIX
D. EtherChannel
Automatic Medium-Dependent Interface Crossover (Auto-MDIX) automatically detects the
required cable connection type (straight-through or crossover) and configures the connection
appropriately, eliminating cabling errors.
5. During a routine network audit, a security engineer discovers that an internal host is
participating in a VLAN hopping attack by exploiting a misconfigured switchport. Which
configuration setting would have prevented this exploit?
A. Enabling port security with sticky MAC addresses
B. Forcing the native VLAN on trunks to match user VLANs
C. Setting switchports connected to end devices to static access mode and disabling DTP
D. Implementing rapid spanning tree across all distribution layers
,VLAN hopping via switch spoofing occurs when an attacker mimics a switch to negotiate a
trunk link via DTP. Ensuring end-user ports are manually set to static access mode and turning
off DTP completely closes this vector.
6. An enterprise router is configured with OSPFv2 across multiple areas. An administrator
notices that Area 1 is configured as a totally stubby area. Which type of Link-State
Advertisement (LSA) is strictly blocked by an ABR from entering a totally stubby area?
A. Type 1 and Type 2
B. Type 3 and Type 4 only
C. Type 3, Type 4, and Type 5
D. Type 7 only
A totally stubby area blocks summary LSAs (Type 3 and 4) as well as external AS-external LSAs
(Type 5). It only allows a default route injected by the ABR, reducing routing table size to the
absolute minimum.
7. A network support technician is analyzing wireless frames in a corporate office and
observes management frames being transmitted continuously. Which management frame
type is responsible for announcing the existence of a wireless network and its capabilities?
A. Probe Request
B. Beacon Frame
C. Association Request
D. Authentication Frame
Access points periodically broadcast Beacon frames to announce their presence, SSID,
supported data rates, and security parameters to wireless clients within range.
8. An administrator is configuring Rapid PVST+ on a campus network and wants to ensure
that a specific distribution switch always becomes the root bridge for VLAN 10. Which
parameter should be adjusted to achieve this deterministically?
A. Increase the hello timer to 4 seconds
B. Set the bridge priority to 0 or another value lower than all other switches
C. Enable bridge assurance on all trunk links
, D. Configure portfast on the root ports
Spanning Tree elects the root bridge based on the lowest bridge ID, which is a combination of
the bridge priority and MAC address. Lowering the priority value ensures the switch is elected
root.
9. A systems engineer is designing an IPv4 subnetting scheme for a new branch office that
requires at least 55 usable host addresses per subnet. Which subnet mask meets this
requirement while wasting the fewest possible IP addresses?
A. 255.255.255.192
B. 255.255.255.128
C. 255.255.255.224
D. 255.255.255.240
A subnet mask of 255.255.255.192 provides a /26 prefix, leaving 6 host bits ($2^6 - 2 = 62$
usable host addresses). A /27 mask only yields 30 usable hosts, which is insufficient.
10. An engineer is configuring a point-to-point serial link between two routers and needs to
ensure that authentication is enforced using a secure, hashed password mechanism without
sending credentials in cleartext. Which protocol should be implemented?
A. PAP
B. CHAP
C. Telnet
D. HTTP
Challenge Handshake Authentication Protocol (CHAP) uses a three-way handshake and an
MD5 hashing algorithm to authenticate a peer without sending the actual password across
the wire, unlike Password Authentication Protocol (PAP) which sends passwords in plaintext.
11. A network operations team is reviewing Syslog messages and notices a critical
hardware failure alert. According to standard Syslog severity rankings, which numeric
level represents a critical condition?
A. Level 0
B. Level 2
Questions And Answers 2026/2027 | Verified Answers Plus
Rationales | Graded Q&A Comprehensive Study Guide |
Verified Latest 2027
1. A network engineer is configuring a new enterprise switch and needs to ensure that
unauthorized switches cannot form trunk links and inject rogue VLAN traffic into the
network. Which protocol should be disabled or configured securely on all user-facing
access ports to mitigate this vulnerability?
A. Spanning Tree Protocol
B. Dynamic Trunking Protocol
C. Link Layer Discovery Protocol
D. Virtual Router Redundancy Protocol
Dynamic Trunking Protocol (DTP) negotiates trunking automatically between Cisco switches.
Leaving access ports in dynamic auto or dynamic desirable modes allows an attacker to plug
in a rogue switch and form a trunk, gaining access to all VLANs. Disabling DTP or setting ports
to static access mode prevents this.
2. An administrator is troubleshooting an IPv6 connectivity issue on a Linux host and
notices that the node is unable to discover neighboring routers on the local link. Which
ICMPv6 message type is specifically utilized by Neighbor Discovery Protocol (NDP) for
router discovery?
A. Type 133
B. Type 135
C. Type 137
D. Type 130
ICMPv6 Type 133 corresponds to Router Solicitation (RS) messages, which hosts send to
discover routers on the link. Type 135 is Neighbor Solicitation, Type 137 is a Redirect Message,
and Type 130 is a Multicast Listener Query.
3. A junior administrator applies an access control list (ACL) to an interface but
mistakenly places an inbound standard ACL on the external interface facing the internet,
,inadvertently blocking internal users from reaching local corporate servers. Where should
standard ACLs ideally be placed in relation to the destination?
A. As close to the source as possible
B. As close to the destination as possible
C. In the middle of the network path
D. On the core distribution layer only
Standard ACLs filter traffic based solely on the source IP address. Because they do not inspect
destination addresses, placing them too close to the source can block unintended traffic
streams. They should always be placed as close to the destination as possible to avoid
collateral routing disruption.
4. A network technician needs to connect two modern Cisco switches using a standard
copper patch cable without crossover wiring. Which feature automatically detects the
signal pairs and configures the interface regardless of the cable type used?
A. Port Aggregation Protocol
B. Link Aggregation Control Protocol
C. Auto-MDIX
D. EtherChannel
Automatic Medium-Dependent Interface Crossover (Auto-MDIX) automatically detects the
required cable connection type (straight-through or crossover) and configures the connection
appropriately, eliminating cabling errors.
5. During a routine network audit, a security engineer discovers that an internal host is
participating in a VLAN hopping attack by exploiting a misconfigured switchport. Which
configuration setting would have prevented this exploit?
A. Enabling port security with sticky MAC addresses
B. Forcing the native VLAN on trunks to match user VLANs
C. Setting switchports connected to end devices to static access mode and disabling DTP
D. Implementing rapid spanning tree across all distribution layers
,VLAN hopping via switch spoofing occurs when an attacker mimics a switch to negotiate a
trunk link via DTP. Ensuring end-user ports are manually set to static access mode and turning
off DTP completely closes this vector.
6. An enterprise router is configured with OSPFv2 across multiple areas. An administrator
notices that Area 1 is configured as a totally stubby area. Which type of Link-State
Advertisement (LSA) is strictly blocked by an ABR from entering a totally stubby area?
A. Type 1 and Type 2
B. Type 3 and Type 4 only
C. Type 3, Type 4, and Type 5
D. Type 7 only
A totally stubby area blocks summary LSAs (Type 3 and 4) as well as external AS-external LSAs
(Type 5). It only allows a default route injected by the ABR, reducing routing table size to the
absolute minimum.
7. A network support technician is analyzing wireless frames in a corporate office and
observes management frames being transmitted continuously. Which management frame
type is responsible for announcing the existence of a wireless network and its capabilities?
A. Probe Request
B. Beacon Frame
C. Association Request
D. Authentication Frame
Access points periodically broadcast Beacon frames to announce their presence, SSID,
supported data rates, and security parameters to wireless clients within range.
8. An administrator is configuring Rapid PVST+ on a campus network and wants to ensure
that a specific distribution switch always becomes the root bridge for VLAN 10. Which
parameter should be adjusted to achieve this deterministically?
A. Increase the hello timer to 4 seconds
B. Set the bridge priority to 0 or another value lower than all other switches
C. Enable bridge assurance on all trunk links
, D. Configure portfast on the root ports
Spanning Tree elects the root bridge based on the lowest bridge ID, which is a combination of
the bridge priority and MAC address. Lowering the priority value ensures the switch is elected
root.
9. A systems engineer is designing an IPv4 subnetting scheme for a new branch office that
requires at least 55 usable host addresses per subnet. Which subnet mask meets this
requirement while wasting the fewest possible IP addresses?
A. 255.255.255.192
B. 255.255.255.128
C. 255.255.255.224
D. 255.255.255.240
A subnet mask of 255.255.255.192 provides a /26 prefix, leaving 6 host bits ($2^6 - 2 = 62$
usable host addresses). A /27 mask only yields 30 usable hosts, which is insufficient.
10. An engineer is configuring a point-to-point serial link between two routers and needs to
ensure that authentication is enforced using a secure, hashed password mechanism without
sending credentials in cleartext. Which protocol should be implemented?
A. PAP
B. CHAP
C. Telnet
D. HTTP
Challenge Handshake Authentication Protocol (CHAP) uses a three-way handshake and an
MD5 hashing algorithm to authenticate a peer without sending the actual password across
the wire, unlike Password Authentication Protocol (PAP) which sends passwords in plaintext.
11. A network operations team is reviewing Syslog messages and notices a critical
hardware failure alert. According to standard Syslog severity rankings, which numeric
level represents a critical condition?
A. Level 0
B. Level 2
