CCNA 200-301 v2 (200-301) — Questions 1576–1650

This option is wrong because a native VLAN mismatch would typically affect all VLANs across the trunk, not just VLAN 30. In this scenario, only VLAN 30 is experiencing connectivity issues, indicating a different problem.

This option is wrong because configuring VLAN 30 as the native VLAN does not directly affect the ability of PCs in VLAN 30 on SwitchA to communicate with servers in VLAN 30 on SwitchB, especially if VLAN 30 is already properly configured on both switches.

SwitchB using ISL instead of 802.1Q is not relevant to the connectivity issue between VLAN 30 on SwitchA and SwitchB. The problem is likely due to VLAN 30 not being allowed on the trunk, not the encapsulation method used.

Disabling DHCP snooping is unnecessary because the other VLANs work, and the scenario does not indicate a trust misconfiguration; the real problem is the incorrect helper address on Vlan20.

This option is wrong because different native VLANs do not prevent an EtherChannel from forming; they can still establish a link if other configurations are compatible. The primary issue in this scenario is related to LACP mode mismatches.

This option is incorrect because EtherChannel can use either PAgP or LACP for negotiation, and both protocols can operate independently of each other. The requirement for both sides to use PAgP in desirable mode is not a necessity for EtherChannel to function.

This option is wrong because EtherChannel can be configured on switch ports without needing to convert them to routed ports. Routed ports are not necessary for EtherChannel to function, as it operates at Layer 2.

This option is wrong because a default gateway does not replace the need for a subnet mask; both are essential for proper IP communication. The subnet mask defines the network portion of an IP address, while the default gateway routes traffic to external networks.

This option is wrong because a default gateway and a DNS server serve different purposes; the default gateway routes traffic outside the local subnet, while a DNS server resolves domain names to IP addresses.

This option is wrong because a default gateway is not limited to ARP broadcasts; it is used for routing packets to destinations outside the local subnet, which involves more than just ARP communication.

Users often think any collision indicator points to both sides being half-duplex, ignoring the known switch configuration.

Late collisions are commonly associated with physical layer issues, leading candidates to assume a cable problem even when explicitly ruled out.

Candidates see input errors and CRC and prematurely conclude a loop or broadcast storm, overlooking that the output shows no broadcast activity and contains late collisions specific to duplex issues.

This option is wrong because good design thinking for guest access requires implementing security measures to protect the network and its resources, even for guests. Completely avoiding security compromises the network's integrity and exposes it to potential threats.

This option is wrong because guest WLANs should have distinct permissions to ensure that guests do not have access to sensitive internal resources, which could lead to security breaches.

This option is wrong because guest access typically requires controller coordination to manage policies, monitoring, and security effectively, ensuring that guest traffic is properly segmented and controlled.

Syslog is incorrect because it only records system events, error messages, and notifications. It does not provide detailed traffic flow or bandwidth usage information, so it cannot help identify which flows consume the most bandwidth.

DHCP relay is incorrect as its function is to forward DHCP broadcast requests from clients to DHCP servers across different subnets. It does not analyze or report on traffic flows or bandwidth consumption.

PortFast is incorrect because it is a Spanning Tree Protocol feature that allows edge ports to transition quickly to the forwarding state. It has no role in traffic flow analysis or bandwidth monitoring.

NAT pool size is not a limiting factor with PAT overload; a single address can serve thousands of hosts.

The interface is correctly configured for NAT inside.

Applying multiple access lists to the same pool is allowed and does not create a conflict.

This option is incorrect because idempotency does not relate to the transport layer protocols like TCP or UDP; it focuses on the behavior of operations in terms of repeated execution leading to the same outcome.

Option C is incorrect because idempotency does not relate to the encryption of device credentials; it refers to the property of operations that can be applied multiple times without changing the result beyond the initial application.

Option D is incorrect because idempotency does not dictate the use of a single management protocol; rather, it refers to the property of operations yielding the same result regardless of how many times they are executed.

A lower AD would make the static route preferred over the dynamic route, not floating.

AD values are integers; 0 is directly connected, and 1 is static. A floating static route must be >1 to be less preferred than a static default.

AD is a static value set at configuration time; it does not auto-adjust.

The specific factual error: Subinterfaces cannot be individually shut/no shut; they depend on the physical interface. Also, adding a route for the local network is redundant.

The specific factual error: The gateway IP must match the PC's configured default gateway. Changing it would break connectivity even if the interface were up.

The specific factual error: The switch configuration may be correct; the issue is specifically on R1's interface. The question asks to fix the problem on R1.

Switches do not automatically convert an access port to a trunk; manual configuration is required.

An access port remains a Layer 2 interface; it does not become a routed Layer 3 interface.

VLANs operate at Layer 2 and are not automatically summarized into a single prefix; that would be a routing function.

This option is incorrect because the principle of least privilege does not imply that administrators should have no configuration access; rather, it means they should only have the access necessary to perform their job functions.

This option is incorrect because least privilege does not eliminate the need for logging and accounting; instead, it complements these practices by ensuring that access is limited while still requiring oversight and tracking of actions taken by users.

This option is incorrect because the principle of least privilege applies to all network environments, not just wireless guest networks. It is a fundamental security concept that should be implemented across all systems and user roles.

Option A describes the shutdown violation mode behavior, where the port immediately goes err-disabled upon detecting a second unauthorized MAC address. Since the command specifies 'violation restrict', the port does not disable but stays up, so this option is incorrect.

Option C is incorrect because port security never forwards traffic from unauthorized MAC addresses. The switch drops such frames to enforce security policies, so forwarding violating traffic is not possible.

Option D is incorrect because listening and learning states refer to Spanning Tree Protocol (STP) port states, not port security violation responses. Port security violation modes do not cause STP state changes.

The 'ip nat inside source list' command must specify the outside interface (the one with the public IP) for translation, not the inside interface.

NAT overload (PAT) requires the 'overload' keyword to enable port address translation. Without it, the router performs dynamic NAT, which is insufficient for sharing a single public IP among many hosts.

The ACL should match only the internal network that requires translation. Using 'permit any' would translate all traffic, including traffic that should not be translated, potentially breaking connectivity or causing security risks.

This option is wrong because a port configured with PortFast and BPDU Guard will not automatically become the root port when it receives BPDUs; instead, it will be error-disabled due to BPDU Guard's protection mechanism.

This option is wrong because a port configured with PortFast does not automatically convert to a trunk port when it receives BPDUs; instead, it remains in access mode. BPDU Guard will cause the port to be error-disabled upon receiving BPDUs, preventing any trunking behavior.

This option is wrong because PortFast does not disable Spanning Tree Protocol (STP) entirely; it merely allows the port to transition to the forwarding state immediately without participating in STP calculations. BPDUs are still processed, and BPDU Guard will take action if they are received.

The default gateway must be an IP on the same subnet as the client, typically the router's LAN interface.

DHCP snooping does not provide DHCP services; it only filters DHCP messages.

The client must first have a valid IP and default gateway; static routes on a host are rarely used and not the issue here.

The APIPA address indicates a DHCP failure, not a DNS problem.

A static IP conflict would not result in an APIPA address; the laptop would show the manually configured IP, not 169.254.x.x.

A physical cable issue would prevent link, so the laptop would not even attempt DHCP and would not get an APIPA address.

Candidates may overlook the explicit mention that the SVIs are up/up, mistakenly thinking a shut SVI could be the problem.

Trunk misconfiguration is a common inter-VLAN issue, but the scenario explicitly says the trunks are working properly, making this answer invalid.

The successful ping to the default gateway proves the gateway is correct. Without 'ip routing', the switch can't forward packets from VLAN 10 to VLAN 20, but it can respond to local VLAN requests.

This statement is too absolute; CRC errors often stem from Layer 1 issues like bad cables or noise, not always a defective port.

The statement is too definitive; giants can be forwarded if jumbo frame support is enabled.

This statement is incorrect because 'show controllers' often includes runt and giant counters on many Cisco platforms.

The native VLAN mismatch is not resolved; the switch likely uses native VLAN 1, so R1 should also use 1 or both sides must be configured consistently.

IP routing is disabled by default on Cisco routers; it must be explicitly enabled for the router to perform routing functions.

Two errors: native VLAN mismatch persists and IP routing is disabled, so packets cannot be routed between VLANs.

The default gateway must be R2's directly connected interface IP (192.0.2.2), not 192.0.2.254. EUI-64 cannot be used if the peer expects a specific static address on the same subnet.

The subnet mask must be consistent on both ends of the link. A /24 mask on one side and /30 on the other creates overlapping subnets and routing issues.

EUI-64 does not guarantee that the resulting IPv6 address will be on the same subnet as a statically configured peer address. For direct connectivity, both routers must have addresses in the same subnet.

This option is wrong because the response is in JSON format, not XML. JSON uses curly braces and key-value pairs, while XML uses tags to define elements.

The hostname field is a string, not a list, as it contains a single value ('Dist-1') and does not represent multiple items or entries.

This option is wrong because the format shown in the response is JSON, not YAML. YAML uses indentation and a different syntax for data representation, which is not present here.

Option B is incorrect because POST does not always replace an existing resource completely; it usually creates new resources or triggers processing. PUT is the method associated with full resource replacement.

Option D is incorrect because REST APIs do not require SNMP as the transport mechanism; they typically use HTTP or HTTPS protocols for communication.

The subnet mask on G0/0 must be /24 to match the connected network; a /30 mask would put R2 in a different subnet. Also, the duplicate IP on G0/1 is not resolved.

IPv6 must be configured on both interfaces to enable IPv6 connectivity. Omitting IPv6 on G0/1 leaves the interface without IPv6 capability.

The subnet mask on G0/0 must be changed to /24 to match the network 198.51.100.0/24. Keeping /30 is the original wrong configuration.

This option is incorrect because EUI-64 does not change the prefix length of an IPv6 address; it is used solely for generating the interface ID from a MAC address within the existing prefix.

This option is incorrect because EUI-64 does not replace the need for a link-local address; link-local addresses are essential for local network communication in IPv6, regardless of how the global address is generated.

This option is wrong because EUI-64 does not encrypt IPv6 traffic; it is used to generate the interface ID from the MAC address, which is unrelated to encryption processes.

Changing the native VLAN to 10 on the switch without a matching 'encapsulation dot1Q 10 native' subinterface on R1 causes native VLAN traffic to be dropped.

Using 'encapsulation dot1Q 1' (without native) tells the router to expect tagged VLAN 1 frames, which will never arrive because the switch sends native VLAN 1 untagged.

Altering the network to make VLAN 10 the native VLAN is unnecessary and can break existing connectivity; the correct fix is to accommodate the existing native VLAN 1 design.

The specific factual error is that 'ip domain lookup' is not the cause of the problem; it is already enabled by default.

The specific factual error is that the problem is not a cached negative response; the DNS server itself lacks the record.

The specific factual error is that 203.0.113.50 is a host address, not a DNS server address.

The specific factual error is that timer mismatches affect the neighbor discovery phase, not the database exchange phase.

The specific factual error is that network type affects the election of DR/BDR and adjacency formation, but not the DBD exchange process.

The specific factual error is that area ID mismatches cause OSPF to ignore hello packets, so the adjacency never progresses beyond DOWN.

Option B, 10.77.4.143, is incorrect because it falls within the usable host range of the subnet defined by 10.77.4.128/28, which spans from 10.77.4.129 to 10.77.4.142. The network address must always be the first address in the subnet.

This option is wrong because 10.77.4.144 is not the network address for the subnet defined by 10.77.4.141/28; the correct network address is 10.77.4.128, which is the first address in the subnet range.

Option D, 10.77.4.112, is incorrect because it does not fall within the subnet defined by the CIDR notation /28, which covers addresses from 10.77.4.128 to 10.77.4.143. The network address for this subnet is 10.77.4.128.

The problem is not due to missing global addresses; the adjacency is stuck at EXSTART, not at DOWN or INIT.

The show output shows different router IDs (192.168.1.1 and 192.168.1.2), so this is not the issue.

The adjacency is stuck in EXSTART, which is not typically resolved by changing network type; the issue is related to packet exchange.

Candidates may think that the ACL itself, if still configured, continues to filter traffic even when not applied to an interface.

A common misunderstanding is that the access-group line can persist without a valid ACL and cause some default behavior; in fact the entire command is removed.

Some candidates may confuse direction changes with removal and assume the ACL is still filtering traffic in some way, but the symptom clearly indicates no filtering at all.

This option is wrong because an SVI (Switched Virtual Interface) for a VLAN cannot be configured as a trunk port; it must be an access port. VLANs are typically assigned to access ports, and changing the SVI to a trunk would not resolve DHCP scope issues.

This option is incorrect because DHCP can support multiple scopes across different VLANs, allowing for distinct address ranges for each VLAN. Thus, having multiple scopes is not a limitation of DHCP itself.

This option is incorrect because DHCP relay does not require clients to use static addresses; it is designed to facilitate dynamic IP address assignment. Static addresses would not affect the relay process or the DHCP server's ability to assign addresses from the correct scope.

The ACL must match the entire inside network (192.168.10.0/24), not just the server IP.

The overload keyword is required to enable PAT (port address translation) for sharing a single public IP among multiple inside hosts.

The interface facing the internet must be configured as ip nat outside; inside interfaces are those facing the internal network.

192.168.40.0/24 is a valid route but less specific than 192.168.40.128/25. Since the destination IP falls within both, the router prefers the more specific /25 route, so this option is incorrect.

0.0.0.0/0 is the default route and only used when no other route matches. Since more specific routes exist for the destination IP, this option is incorrect.

Overlapping routes like /24 and /25 are common and resolved by longest prefix match. The presence of overlapping entries does not prevent route selection, so this option is incorrect.

Mismatched OSPF process IDs do not prevent neighbor formation because process IDs are locally significant identifiers on each router. They do not need to match for adjacency to form, so this option is incorrect.

Missing default routes do not affect OSPF neighbor formation. Default routes influence routing decisions but are not required for establishing OSPF adjacencies, so this option is incorrect.

Different router IDs are necessary for OSPF neighbors to uniquely identify each router. Having different router IDs does not cause adjacency failure, so this option is incorrect.

A default route on the inside host controls outbound traffic, not inbound connections from the internet.

PAT overload is used for many-to-one translation and would not block inbound traffic if static NAT is already configured.

DHCP relay forwards DHCP requests to a remote server and does not affect inbound HTTP/HTTPS access to a web server.

Incorrect. PPP authentication applies to serial interfaces and point-to-point links, but the exhibit shows a GRE tunnel configuration, not PPP on a serial link.

Incorrect. WPA3 is a wireless security protocol unrelated to GRE tunnels, which operate at Layer 3 and do not configure wireless security settings.

Incorrect. GRE tunnels do not automatically enable BGP or any routing protocol; routing protocols must be explicitly configured over the tunnel interface.

The specific factual error: The domain name is mandatory for RSA key generation in SSH configuration.

The specific factual error: Vty lines require transport input ssh to allow SSH connections.

The specific factual error: The key size must be 2048 bits as specified; 1024 bits is insufficient.

PAT overload is incorrect because it is designed for many internal hosts sharing a single public IP for outbound traffic, not for providing a fixed public IP for inbound server access.

No NAT is incorrect since private IPv4 addresses are not routable on the public Internet; without NAT, the internal server cannot be reached from outside the private network.

DHCP relay is unrelated to NAT or public reachability; it only forwards DHCP requests across subnets and does not provide any public IP mapping for internal servers.

The show output indicates Layer 2 mode is already active, and trunking isn’t required for bundling. The issue is LACP protocol negotiation, not interface mode.

The Port-channel would still form even with a native VLAN mismatch; it would not be down (SD) and ports would not be stand-alone (I) solely because of VLAN mismatch.

The flags in the output (I, SD) are not consistent with a speed/duplex problem, and the explicit configuration of passive mode on both sides is the known root cause.

Encapsulation problems cause protocol failures, not corrupted frames with CRC errors.

Candidates often mistake high CRC counts for duplex issues. The absence of collision-related counters rules out a duplex mismatch.

A wrong VLAN does not generate CRC errors on the physical interface.

This option is wrong because the question specifies that the PC cannot reach the default gateway due to VLAN issues, not because of port security settings. Port security would typically result in the interface being in an error-disabled state, which is not indicated here.

This option is incorrect because converting the port to a trunk would not resolve the issue of the PC not reaching the default gateway if VLAN 20 is not configured or active. The problem lies in the VLAN configuration, not the port type.

This option is incorrect because the default gateway is typically configured on the device (e.g., a router or PC) rather than on the switch port itself. The issue in the question pertains to VLAN configuration, not gateway settings.

The specific factual error: 'restrict' does not disable the port; it only filters traffic and logs the violation, but the port remains operational.

The specific factual error: 'protect' silently drops unauthorized traffic without logging or disabling the port.

The specific factual error: PortFast is required to bypass STP convergence; without it, the port will wait for STP to transition, causing delay.

Syslog is not used for IP address assignment; that function is performed by DHCP.

Syslog does not replace SNMP counters for interface statistics; SNMP remains the primary method for collecting such data.

This is incorrect because spam classification is a supervised learning problem, not a reinforcement learning one.

This is incorrect because clustering groups data, it doesn't forecast numeric values like bandwidth usage.

This is incorrect because predictive analytics typically involves dynamic ML models, not just static thresholds.

Availability is incorrect because it focuses on ensuring that systems and data are accessible when needed, not on preventing unauthorized data modification.

Accounting is incorrect since it involves logging and tracking user activities and network events but does not guarantee that the data itself has not been altered.

Confidentiality is incorrect because it protects data from unauthorized disclosure but does not ensure that the data has not been changed or tampered with.

Syslog is incorrect because it focuses on logging device events and messages rather than providing traffic flow or volume information necessary for identifying heavy traffic sources.

DHCP is incorrect since it only assigns IP addresses and network settings to hosts and does not offer any insight into traffic patterns or flow data.

PortFast is incorrect because it is a Spanning Tree Protocol feature that accelerates port forwarding state transitions and does not relate to traffic monitoring or analysis.

Misunderstanding that DAI controls DHCP traffic rather than ARP packets.

Assuming DHCP snooping introduces routing changes or that the server is on a different subnet.

Confusing DHCP snooping with DHCP relay agent functionality and option 82 insertion.

Priority 0 excludes the router from DR/BDR election entirely; it can only become a DROTHER.

A new router with a higher priority does not trigger a new election unless the existing DR or BDR goes down.

DROTHERs do not form full adjacencies among themselves; they only exchange LSAs via the DR/BDR.

Although removing 'passive-interface default' would also restore OSPF on these interfaces, the solution commands show the preferred method of overriding the default selectively, making this option incorrect for the given scenario.

The network statements on R1 already correctly include the /30 subnets, so there is no need to change wildcard masks.

The OSPF network type defaults to broadcast, which is appropriate for Ethernet links; changing to point-to-point does not resolve the passive-interface issue and would not fix hello suppression.

DHCP snooping and DAI (Dynamic ARP Inspection) do not address the requirement of disabling a port upon receiving BPDUs; they focus on protecting against rogue DHCP servers and ARP spoofing, respectively.

Root Guard and VTP pruning do not address the requirement of quickly enabling access ports and disabling them upon receiving BPDUs. Root Guard is used to prevent a port from becoming a root port, while VTP pruning optimizes VLAN traffic, neither of which directly manage port states based on BPDU reception.

Port security and CDP do not provide the necessary functionality to disable a port when BPDUs are received. Port security can limit the number of MAC addresses but does not specifically address BPDU handling.

TTL is not the main distinguishing value PAT uses because it changes as packets traverse routers and does not uniquely identify individual flows in NAT translations.

DSCP is a QoS marking used to prioritize traffic and does not play a role in NAT or PAT flow differentiation, so it cannot distinguish inside flows sharing one outside IP.

MAC addresses are Layer 2 addresses that are not preserved across routed NAT boundaries, so they cannot be used to distinguish flows in PAT.

POST is incorrect because it is used to create new resources or submit data that modifies the server state, not for retrieving existing data. Selecting POST would imply changing the resource, which contradicts the question's requirement for a non-modifying method.

PUT is incorrect as it replaces or updates an existing resource entirely. It modifies the resource state, which is not the intended action when simply retrieving data from a REST API.

DELETE is incorrect because it removes a resource from the server. Using DELETE would modify the resource by deleting it, which is the opposite of the question's intent to retrieve data without modification.

NTP authentication protects the integrity of time synchronization between devices but does not provide any mechanism for monitoring or analyzing network traffic flows or bandwidth usage.

DNS forwarding improves domain name resolution efficiency but does not collect or analyze traffic flow information related to bandwidth consumption.

DHCP snooping is a security feature that prevents unauthorized DHCP servers at Layer 2 and does not provide any traffic profiling or bandwidth monitoring capabilities.

OSPF routes are installed when EIGRP is present; routing protocols coexist and the route with the lowest AD is selected.

OSPF supports both IPv4 and IPv6; it is not limited to IPv6.

EIGRP routes do not always have a smaller subnet mask; prefix length is determined by the network design, not the routing protocol.

Using a trunk port for a single device connection is unnecessary and violates standard access port design; it would also require the phone to support trunking, which is not the typical Cisco IP phone configuration.

STP does not introduce significant delays in normal operation, and disabling it risks broadcast storms and network loops.

Access ports operate at Layer 2; converting to a routed port would prevent the phone and PC from communicating within their respective VLANs.

A floating static route is configured with a higher administrative distance than the primary route, not lower.

A directly connected route has an administrative distance of 0, which is preferred over a static route with AD 1.

IPv4 static routes use the 'ip route' command, while IPv6 static routes use the 'ipv6 route' command; the syntax is different.

Converting all inside hosts to the same private IP would cause addressing conflicts and break basic connectivity, not enable PAT.

Increasing the NAT pool provides more public addresses but does not allow many users to share one public address via port translation.

Static NAT requires a dedicated public IP per host, preventing many-to-one sharing.