View Full Cisco 350-401 Exam Dumps and Practice Test Dumps

 

Question 381

Which Cisco feature can prevent a switch port from becoming an STP root port because of superior BPDUs received from an unauthorized switch?

1. BPDU Guard
2. PortFast
3. Root Guard
4. Loop Guard

Correct Answer: 3

Explanation

Root Guard prevents an interface from becoming a root port when superior Bridge Protocol Data Units (BPDUs) are received. It is useful on ports where the administrator does not expect another switch to influence the spanning-tree root position. If a superior BPDU is received, the port can enter a root-inconsistent state until the superior information is no longer received. This helps maintain the intended STP topology. BPDU Guard is primarily used to protect PortFast-enabled edge ports from unexpected BPDUs.

Question 382

Which BGP message is used to establish session parameters when two BGP peers first connect?

1. OPEN
2. UPDATE
3. KEEPALIVE
4. NOTIFICATION

Correct Answer: 1

Explanation

BGP peers exchange OPEN messages after establishing the underlying TCP connection. The OPEN message contains important session parameters such as the BGP version, autonomous system number, BGP identifier, and Hold Time. After successful negotiation, the peers can exchange routing information using UPDATE messages and maintain the session with KEEPALIVE messages. NOTIFICATION messages are used to report errors and terminate sessions. The OPEN message is therefore the key BGP message responsible for negotiating and establishing the parameters of a new BGP peering session.

Question 383

What is the primary purpose of an SVI on a multilayer switch?

1. To provide a Layer 3 interface for a VLAN
2. To negotiate EtherChannel
3. To mirror switch traffic
4. To prevent STP loops

Correct Answer: 1

Explanation

A Switched Virtual Interface (SVI) is a virtual Layer 3 interface associated with a VLAN on a multilayer switch. It can provide the default gateway for devices within that VLAN and participate in routing between VLANs when IP routing is enabled. SVIs eliminate the need for a separate physical router interface for every VLAN in many campus designs. EtherChannel negotiation, traffic mirroring, and spanning-tree loop prevention are handled by other technologies. SVIs are therefore fundamental to inter-VLAN routing on multilayer switches.

Question 384

Which protocol allows a network management application to retrieve and modify structured configuration data from a device using XML-based messages?

1. RESTCONF
2. NETCONF
3. SCP
4. TFTP

Correct Answer: 2

Explanation

NETCONF is a network management protocol designed for installing, manipulating, and retrieving configuration data. It commonly uses XML-based messages and operates over a secure transport such as SSH. NETCONF works with YANG data models to provide structured and predictable configuration operations. RESTCONF provides similar capabilities through REST-style HTTP methods and commonly uses JSON or XML representations. SCP and TFTP are file-transfer protocols rather than structured network configuration protocols. NETCONF is therefore particularly useful for programmatic configuration management and network automation.

Question 385

Which OSPF packet is periodically sent to discover and maintain neighboring routers?

1. Hello
2. Database Description
3. Link-State Request
4. Link-State Acknowledgment

Correct Answer: 1

Explanation

OSPF Hello packets are periodically transmitted to discover neighboring routers and maintain established neighbor relationships. Hello packets contain information such as the router ID, area ID, timers, network mask, and other parameters that must be compatible for adjacency formation. If expected Hello messages are not received within the configured dead interval, the neighbor relationship can be declared down. Database Description packets synchronize link-state databases, Link-State Requests request specific LSAs, and acknowledgments confirm LSA receipt. Hello packets are therefore fundamental to OSPF neighbor discovery and maintenance.

Question 386

Which QoS mechanism limits traffic to a configured rate by dropping or remarking packets that exceed the permitted rate?

1. Queuing
2. Policing
3. Shaping
4. Classification

Correct Answer: 2

Explanation

QoS policing enforces a traffic-rate limit by monitoring traffic against a configured rate and taking action when traffic exceeds that limit. Excess packets may be dropped or remarked according to the policy. Unlike shaping, policing does not normally hold excess packets in a buffer to transmit them later. Classification identifies traffic, while queuing determines how packets are scheduled during congestion. Policing is therefore appropriate when an administrator needs to enforce a maximum traffic rate and control what happens to packets that exceed the defined bandwidth allowance.

Question 387

Which routing feature allows a router to advertise a single summarized prefix instead of multiple more-specific routes?

1. Route summarization
2. Port security
3. Route reflection
4. NAT

Correct Answer: 1

Explanation

Route summarization combines multiple contiguous network prefixes into a larger summary prefix. Instead of advertising numerous individual routes, a router can advertise one summarized route, reducing routing-table size and routing-update overhead. Summarization can also help limit the propagation of topology changes and improve routing scalability. Route reflection is a BGP scalability mechanism for iBGP, NAT translates addresses, and Port Security controls Layer 2 access. Properly designed summarization can make large networks more efficient while reducing unnecessary routing information between network areas.

Question 388

Which protocol is used by Cisco devices to exchange VLAN trunking information in environments where VTP is enabled?

1. DTP
2. CDP
3. VTP
4. LLDP

Correct Answer: 3

Explanation

VLAN Trunking Protocol (VTP) is a Cisco proprietary protocol that can distribute VLAN information between switches within a VTP domain. Depending on the configured VTP mode and version, switches can learn, create, modify, or synchronize VLAN information through VTP advertisements. DTP is used for negotiating trunking, CDP provides Cisco neighbor discovery, and LLDP is a vendor-neutral neighbor discovery protocol. VTP should be deployed carefully because VLAN database changes can affect multiple switches. Its primary function is distributing VLAN configuration information.

Question 389

Which IPv6 mechanism uses Router Solicitation and Router Advertisement messages to help hosts discover routers?

1. Neighbor Discovery Protocol
2. NAT
3. DHCP
4. ARP

Correct Answer: 1

Explanation

IPv6 Neighbor Discovery Protocol (NDP), based on ICMPv6, provides mechanisms for router discovery and several other local-link functions. Hosts can send Router Solicitation messages to request information, while routers respond with Router Advertisement messages containing information such as prefixes and default-router details. NDP also supports neighbor reachability and duplicate address detection. IPv6 does not use ARP for these functions. DHCP can provide additional configuration information, but router discovery itself is performed through ICMPv6 Neighbor Discovery mechanisms.

Question 390

Which BGP attribute is normally considered before MED when comparing paths from different sources?

1. Origin
2. Router ID
3. Local Preference
4. Community

Correct Answer: 3

Explanation

Local Preference is an important BGP path-selection attribute and is evaluated before MED in the standard Cisco BGP best-path process. Higher Local Preference values are preferred and influence which exit path an autonomous system uses for outbound traffic. MED is considered later and is generally used to influence how a neighboring autonomous system selects among multiple entry points. Communities are mainly used as policy tags, while Router ID can serve as a later tie-breaker. Local Preference therefore has greater influence in the relevant path-selection sequence.

Question 391

Which wireless architecture centralizes the management and control of multiple lightweight access points?

1. Autonomous AP architecture
2. Controller-based architecture
3. Peer-to-peer architecture
4. Hub-based architecture

Correct Answer: 2

Explanation

A controller-based wireless architecture uses a centralized wireless LAN controller to manage multiple lightweight access points. The controller can provide centralized configuration, security policies, RF management, mobility functions, and monitoring. This approach simplifies administration because common settings and operational policies can be managed from a central platform. Autonomous access points operate with more independent configuration, while peer-to-peer and hub-based architectures do not provide the same centralized WLAN management model. Controller-based designs are therefore widely used in enterprise wireless networks requiring consistent centralized administration.

Question 392

Which protocol can provide device discovery information in a multivendor network without relying on Cisco proprietary mechanisms?

1. CDP
2. LLDP
3. VTP
4. DTP

Correct Answer: 2

Explanation

Link Layer Discovery Protocol (LLDP) is an IEEE-standard, vendor-neutral neighbor discovery protocol. It allows compatible network devices from different manufacturers to advertise information such as device identity, interface details, capabilities, and management addresses. CDP provides similar discovery functionality but is Cisco proprietary. VTP distributes VLAN information in supported Cisco environments, while DTP is used for trunk negotiation. LLDP is particularly useful in multivendor networks where administrators need a common method for discovering directly connected infrastructure devices.

Question 393

Which BGP mechanism reduces the need for a full mesh of internal BGP sessions?

1. Route reflector
2. AS Path prepending
3. MED
4. Local Preference

Correct Answer: 1

Explanation

A BGP route reflector reduces the requirement for a full mesh of iBGP sessions within an autonomous system. Instead of every iBGP router maintaining a session with every other iBGP router, selected clients can establish sessions with a route reflector. The reflector then redistributes selected BGP routes between its clients according to route-reflection rules. This improves scalability in large networks by significantly reducing the number of required peer relationships. AS Path prepending, MED, and Local Preference influence routing decisions but do not solve the iBGP full-mesh scalability problem.

Question 394

Which protocol is used to automatically negotiate trunking parameters between compatible Cisco switch interfaces?

1. LACP
2. DTP
3. STP
4. VTP

Correct Answer: 2

Explanation

Dynamic Trunking Protocol (DTP) is a Cisco proprietary protocol used to negotiate trunking behavior between compatible switch interfaces. Depending on the configured modes, interfaces can dynamically determine whether a trunk should be established. Administrators may also manually configure trunking instead of relying on negotiation. LACP negotiates link aggregation, STP prevents Layer 2 loops, and VTP distributes VLAN information. DTP should be controlled carefully in secure network designs because automatically negotiated trunking can potentially expose additional VLANs if an unauthorized device is connected.

Question 395

Which network assurance technology records detailed flow information that can be used to identify high-bandwidth applications?

1. NetFlow
2. CDP
3. TFTP
4. DTP

Correct Answer: 1

Explanation

NetFlow records summarized information about network traffic flows and can provide visibility into source and destination addresses, ports, protocols, packet counts, and byte counts. This information allows administrators to identify high-bandwidth applications, major traffic sources, unusual communication patterns, and utilization trends. NetFlow does not normally capture every packet like a packet analyzer connected to a SPAN destination. CDP provides neighbor information, TFTP transfers files, and DTP negotiates trunking. NetFlow is therefore an important network-assurance technology for understanding traffic behavior and utilization.

Question 396

Which IPv4 protocol is used by a host to discover the Layer 2 MAC address associated with a known IPv4 address?

1. ICMP
2. DHCP
3. ARP
4. DNS

Correct Answer: 3

Explanation

Address Resolution Protocol (ARP) maps a known IPv4 address to the corresponding Layer 2 MAC address on a local network. When a host needs to send an Ethernet frame to an IPv4 destination on the local subnet and does not know the destination MAC address, it can broadcast an ARP Request. The device owning the requested IPv4 address responds with its MAC address, allowing the sender to construct the Ethernet frame. DHCP assigns network parameters, DNS resolves names, and ICMP supports diagnostic and control messaging.

Question 397

Which network design principle divides an enterprise campus into access, distribution, and core layers?

1. Flat network design
2. Three-tier hierarchical design
3. Peer-to-peer design
4. Point-to-point design

Correct Answer: 2

Explanation

The three-tier hierarchical campus design divides the network into access, distribution, and core layers. The access layer connects end devices, the distribution layer provides aggregation and policy functions, and the core layer provides fast and resilient transport between distribution blocks. This separation improves scalability, manageability, and fault isolation. A flat network lacks clear hierarchical boundaries and can become difficult to scale as the environment grows. Hierarchical design also allows administrators to apply appropriate redundancy, routing, and security policies at different architectural levels.

Question 398

Which IPv4 mechanism automatically assigns an address from the 169.254.0.0/16 range when normal DHCP address assignment fails?

1. APIPA
2. PAT
3. NAT
4. SLAAC

Correct Answer: 1

Explanation

Automatic Private IP Addressing (APIPA) allows an IPv4 host to automatically select an address from the 169.254.0.0/16 link-local range when it cannot obtain an address through DHCP. APIPA addresses are intended for local-link communication and are generally not routable across routers. PAT and NAT provide address translation, while SLAAC is an IPv6 address-configuration mechanism. APIPA can help devices communicate locally during DHCP failures, but it does not provide normal enterprise-wide connectivity because link-local IPv4 addresses are not designed for routed communication.

Question 399

Which protocol provides secure, structured access to YANG-modeled configuration data through HTTP-based operations?

1. RESTCONF
2. Syslog
3. SNMP
4. FTP

Correct Answer: 1

Explanation

RESTCONF provides a REST-style interface for accessing and manipulating configuration and operational data modeled with YANG. It typically uses HTTPS and standard HTTP methods such as GET, POST, PUT, PATCH, and DELETE. This makes RESTCONF well suited for modern network automation applications that use web-based APIs. Syslog transports event messages, SNMP provides monitoring and management capabilities through managed objects, and FTP is a file-transfer protocol. RESTCONF combines structured YANG data with familiar web-based operations, making it useful for programmable network management.

Question 400

Which routing technique allows a router to forward selected traffic through a specified next hop based on packet attributes such as source address?

1. Default routing
2. ECMP
3. Policy-Based Routing
4. Route summarization

Correct Answer: 3

Explanation

Policy-Based Routing (PBR) allows administrators to override normal destination-based routing decisions for selected traffic. A route map can match criteria such as source address, protocol, or other packet characteristics and then specify a particular next hop or forwarding action. This can be useful when certain applications or users need to follow a different path from normal traffic. Default routing provides a general fallback route, ECMP uses multiple equal-cost paths, and route summarization reduces routing information. PBR provides granular policy-based control over traffic forwarding.