Implementing and Operating Cisco Enterprise Network Core Technologies (ENCOR) v1.2 practice questions
237 free questions with answers and explanations.
- 1.A network engineer is configuring a new Catalyst 9300 switch. The requirement is to ensure that only authenticated devices can access the network through specific access ports. Which security feature should be configured to meet this requirement, allowing the switch to dynamically learn and secure MAC addresses based on authentication?Infrastructure
- 2.A network security team needs to monitor traffic traversing a critical server farm for anomalies and potential intrusions without impacting the performance of the production network devices. They require a solution that can copy traffic from multiple source ports to a dedicated analysis device. Which network monitoring feature is most suitable for this scenario?Infrastructure
- 3.A network engineer is troubleshooting a multicast video distribution system. Users in different VLANs are unable to receive the multicast stream, even though the source is active and PIM is configured on the router interfaces. The engineer suspects a Layer 2 issue preventing multicast traffic from reaching the PIM-enabled interfaces. Which Layer 2 protocol is essential for forwarding multicast traffic to interested hosts within a VLAN and should be checked?Infrastructure
- 4.A network engineer needs to configure a Cisco router to automatically perform a series of commands if the CPU utilization exceeds 90% for a sustained period. This automation should also log a message to syslog. Which Cisco feature should the engineer use to implement this proactive monitoring and automated response?Infrastructure
- 5.A network engineer needs to configure a Cisco router to synchronize its time with a reliable external time source. The router should act as a client and periodically poll a designated NTP server to maintain accurate time. Which command is used to configure the router as an NTP client to synchronize with a specified server?Infrastructure
- 6.A network engineer is configuring an access layer switch for a new office floor. The switch needs to support Voice over IP (VoIP) phones, which are daisy-chained behind desktop computers. To ensure optimal voice quality, the VoIP phones must receive an IP address from a specific VLAN (VLAN 10 for voice) and prioritize their traffic. The desktop computers connected to the phones should receive an IP address from a different VLAN (VLAN 20 for data). Which feature allows the switch to automatically assign the phone to the voice VLAN and the PC to the data VLAN on a single port?Infrastructure
- 7.A network engineer is configuring a new Cisco Catalyst 9300 switch. The switch needs to support multiple VLANs and ensure that all inter-VLAN routing is performed efficiently in hardware. Which technology is crucial for achieving high-performance inter-VLAN routing on this switch?Infrastructure
- 8.A network engineer troubleshooting a remote branch office router notices that the router's logs are not being sent to the central syslog server. Upon investigation, they find that the router's clock is significantly out of sync, displaying a date several years in the past. Which of the following is the most likely reason for the syslog messages not being received by the central server, assuming the server has correct time window configurations?Infrastructure
- 9.A network engineer is configuring a new Cisco router to support a remote branch office. The branch office uses private IPv4 addresses and needs to access external public resources. The engineer wants to conserve public IP addresses by allowing multiple internal hosts to share a single public IP address. Which NAT type should be configured?Infrastructure
- 10.A network security engineer is implementing a new policy to prevent unauthorized devices from connecting to the corporate network via switch ports. The policy states that only devices with specific MAC addresses should be allowed to transmit traffic on certain access ports. Any device attempting to connect with an unapproved MAC address should trigger an alert and shut down the port. Which Layer 2 security feature should the engineer configure?Infrastructure
- 11.A network architect is designing a wireless network for a large campus. The design requires central management of access points, seamless client roaming across different APs and controllers, and robust security features like 802.1X. Which wireless architecture would best meet these requirements?Infrastructure
- 12.A large enterprise network spans multiple geographical locations, and accurate time synchronization across all devices is critical for log correlation, security forensics, and proper operation of time-sensitive applications. The network architect needs to implement a highly accurate and resilient time synchronization solution that can handle potential failures of primary time sources. Which time synchronization protocol should be deployed, and what specific design consideration ensures resilience?Infrastructure
- 13.A network engineer is troubleshooting a recently deployed application that uses UDP for real-time video streaming. Users are reporting significant quality degradation, including pixelation and freezing. The engineer suspects network congestion is causing packet loss and jitter. Which QoS mechanism should be prioritized to mitigate these issues for UDP-based real-time video?Infrastructure
- 14.A network architect is designing a wireless network for a large university campus with thousands of users. The design requires centralized management of Access Points (APs), seamless roaming for clients across buildings, and consistent application of security policies. Which wireless architecture best meets these requirements?Infrastructure
- 15.A network engineer is troubleshooting a performance issue where a specific application's traffic experiences high latency and packet loss when traversing a congested WAN link. The application uses UDP on port 5000. The engineer needs to apply a QoS policy that marks this application's traffic with a specific DSCP value (e.g., EF for Expedited Forwarding) so that downstream devices can prioritize it. Which QoS component is responsible for identifying and marking specific traffic flows?Infrastructure
- 16.A network architect is designing a wireless network for a large university campus with thousands of users and a high density of devices. The design requires centralized management, seamless roaming between access points (APs) across multiple buildings, and dynamic RF management to optimize coverage and capacity. Which wireless architecture is best suited for these requirements?Infrastructure
- 17.A network administrator is troubleshooting slow network performance for users connected to a specific access layer switch. They suspect a Layer 2 loop. Which of the following commands would best help identify the MAC addresses being learned on multiple ports of that switch?Infrastructure
- 18.A network architect is designing a wireless network for a large university campus with thousands of users. The design requires centralized control over access points, seamless roaming for students and faculty across buildings, and simplified management of wireless policies and security. Which wireless architecture best meets these requirements?Infrastructure
- 19.A network security team needs to monitor traffic traversing a critical server farm for anomalies and potential security threats. The requirement is to capture all ingress and egress traffic for specific VLANs on a core switch without disrupting the normal traffic flow. The captured traffic needs to be sent to an intrusion detection system (IDS) located on a different switch in the same data center. Which monitoring feature should be configured?Infrastructure
- 20.A network engineer is configuring a Cisco router to use NTP. The router needs to synchronize its clock with a highly accurate external time source. The engineer wants to ensure that the router not only receives time updates but also actively checks the accuracy and integrity of the time source and uses a fallback mechanism if the primary source becomes unreliable. Which NTP mode should be configured on the router to achieve this robust synchronization?Infrastructure
- 21.A network operations team is monitoring network performance and needs to collect detailed information about IP traffic flows for billing, security analysis, and capacity planning. They require data such as source/destination IP addresses, ports, protocols, and byte counts for all conversations traversing key routers. Which network service provides this type of flow-based telemetry?Infrastructure
- 22.A network administrator needs to automate a recurring task on a Cisco router: every Sunday at 3:00 AM, the router should clear its BGP neighbor statistics and then send a syslog message indicating the completion of this action. The administrator wants to configure an embedded automation tool on the router itself to perform this sequence of commands automatically. Which Cisco IOS XE feature allows for this type of event-driven or scheduled automation?Infrastructure
- 23.A network engineer is troubleshooting a recently deployed application that uses UDP for real-time video streaming. Users are reporting occasional video stuttering and pixelation, indicating potential packet loss or out-of-order delivery. The engineer suspects that the network's QoS policy might not be correctly prioritizing this traffic. Which QoS mechanism is specifically designed to ensure that critical traffic, like real-time video, receives preferential treatment and is transmitted before other less critical traffic?Infrastructure
- 24.A network engineer is configuring a Cisco router to synchronize its time with a reliable external source. The router is in a secure network segment and can only initiate connections outbound. The engineer wants the router to actively poll a specific NTP server and also be able to serve time to other internal devices. Which NTP mode configuration best suits these requirements?Infrastructure
- 25.A network engineer is troubleshooting a recently deployed application that uses UDP for real-time communication. Users report intermittent connectivity and performance issues, but a basic ping to the server is successful. The firewall team confirms no explicit blocks. Which IP Services feature could help diagnose if the UDP traffic is successfully reaching the server's application port and if the response path is functional?Infrastructure
- 26.A network architect is designing a multicast solution for a video conferencing system that needs to operate across multiple VLANs and subnets within an enterprise. The solution must ensure that multicast traffic is only forwarded to segments where active receivers exist, to conserve bandwidth and prevent flooding. Which Layer 3 multicast routing protocol should be implemented to achieve this efficient, receiver-driven distribution?Infrastructure
- 27.A network engineer is troubleshooting slow application performance between two data centers. Packet captures show high latency and packet loss. The engineer suspects that the traffic is being treated as best-effort. The application uses UDP on port 5000. Which QoS mechanism should the engineer implement to ensure preferential treatment for this application traffic?Infrastructure
- 28.A network engineer is designing a highly available data center network. The design requires that critical servers have their network interfaces connected to two different switches, and these interfaces operate as a single logical link for increased bandwidth and redundancy. If one physical link or switch fails, traffic should automatically reroute over the remaining active link without interruption. Which Layer 2 technology should be used to achieve this?Infrastructure
- 29.A data center network uses multiple Layer 3 switches for routing between VLANs. Engineers observe that traffic between certain VLANs is experiencing suboptimal forwarding paths, specifically that packets are being forwarded to a router that is not the most optimal path, even though a better path exists. All switches are running OSPF. Which feature, if misconfigured or missing, could lead to this suboptimal Layer 3 forwarding issue?Infrastructure
- 30.A network engineer is troubleshooting an intermittent connectivity issue for several end-users connected to a Cisco Catalyst switch. The issue appears to be related to excessive broadcast traffic causing network slowdowns. The engineer suspects a misconfigured device or a loop creating a broadcast storm. Which Layer 2 feature can be configured on the switch ports to prevent excessive broadcast traffic from consuming all available bandwidth?Infrastructure
- 31.A company has implemented a new VoIP system, and users are reporting dropped calls and poor audio quality, characterized by choppiness and delays. The network administrator suspects network congestion is causing these issues. Which QoS mechanism should be configured on the network devices to prioritize VoIP traffic and ensure its quality?Infrastructure
- 32.A network engineer is configuring a new Layer 3 routing switch to act as the default gateway for multiple VLANs. The requirement is to provide redundant default gateway functionality for end-user devices, ensuring high availability in case of a single device failure. Which First Hop Redundancy Protocol (FHRP) should be configured to meet this requirement, allowing for active/standby redundancy?Infrastructure
- 33.A network engineer is configuring a Layer 3 switch to act as a default gateway for multiple VLANs in a campus network. To provide high availability, the engineer wants to ensure that if the primary switch fails, another redundant Layer 3 switch can automatically take over the default gateway role with minimal disruption. Which protocol should be configured?Infrastructure
- 34.A network technician is configuring an NTP server on a Cisco router. The router needs to synchronize its clock with a reliable external time source. Which of the following commands correctly configures the router to act as an NTP client and synchronize with a server at 203.0.113.10?Infrastructure
- 35.A network engineer is configuring a Cisco Catalyst 9300 switch and needs to ensure that all directly connected Cisco IP phones receive their configuration and firmware updates from a specific TFTP server. The engineer wants the switch to automatically provide the TFTP server IP address and other voice-related parameters to the phones upon connection. Which feature should be configured on the switch?Infrastructure
- 36.A network administrator is troubleshooting an intermittent connectivity issue for several devices in a specific VLAN. The devices are connected to a Cisco Catalyst 9300 switch. The administrator suspects a broadcast storm might be occurring. Which Layer 2 feature, when enabled, can help mitigate the impact of excessive broadcast traffic?Infrastructure
- 37.A network engineer needs to configure a Cisco router to translate internal private IP addresses to a single public IP address when accessing the internet. This setup should allow multiple internal hosts to share the same public IP. Which NAT type should be configured?Infrastructure
- 38.A large-scale data center network uses OSPF as its interior gateway protocol. Due to an increase in multicast video streaming services, the network team needs to ensure efficient delivery of multicast traffic to specific receivers across the OSPF domain. The receivers dynamically join and leave multicast groups. Which multicast routing protocol should be configured to support this sparse mode multicast environment?Infrastructure
- 39.A network engineer is designing a new branch office network. Due to budget constraints, the branch will use a single internet connection, and all internal users need to access external resources. The design specifies that internal hosts use private IP addresses. Which network service must be configured on the branch router to allow these internal hosts to communicate with the internet?Infrastructure
- 40.A network engineer is configuring a new Cisco router that will serve as the default gateway for a critical server farm. To ensure high availability, the engineer needs to implement a solution where two routers can act as a single virtual router, sharing a virtual IP address and MAC address. If the primary router fails, the secondary router should automatically take over the active role without any disruption to the servers. Which Layer 3 redundancy protocol should be configured?Infrastructure
- 41.A company is experiencing intermittent voice quality issues (jitter and packet loss) on its VoIP calls, especially during peak network usage. The network uses a combination of Cisco Catalyst switches and routers. Which QoS mechanism, when implemented end-to-end, would be most effective in ensuring preferential treatment for voice traffic over other data traffic?Infrastructure
- 42.A network engineer is configuring a new Cisco router to provide Internet access for a small office. The office uses private IPv4 addresses (10.0.0.0/8) internally, and the router has a single public IPv4 address assigned to its WAN interface. The engineer needs to configure a mechanism that allows multiple internal devices to share this single public IP address when accessing the Internet. Which IP service should be configured?Infrastructure
- 43.A network administrator needs to automate a recurring task on a Cisco router: every Sunday at 3:00 AM, the router should clear its BGP neighbor statistics and then send an email notification to the network operations team upon completion. This automation needs to be performed directly on the router without external scripting servers. Which Cisco feature allows for this type of on-device automation and event-driven scripting?Infrastructure
- 44.A network operations team is implementing a new monitoring solution that requires detailed, real-time information about network traffic flows, including source/destination IP addresses, ports, protocols, and byte counts. The team needs to analyze bandwidth usage, identify top talkers, and detect anomalies across multiple network devices. Which technology is best suited for collecting this type of data?Infrastructure
- 45.A network engineer is deploying a new service that requires precise, deterministic measurement of end-to-end delay and jitter between two Cisco routers. The measurements need to be active, synthetic, and scheduled to run periodically to monitor the service level agreement (SLA). Which network service should the engineer configure on the routers to achieve these active performance measurements?Infrastructure
- 46.A network operations team is implementing a new monitoring solution that requires detailed information about application performance and latency between various network segments. They need to generate synthetic traffic to specific destinations and measure metrics like response time, jitter, and packet loss. Which network service is best suited for this proactive performance monitoring?Infrastructure
- 47.A network engineer is configuring a new Layer 3 switch to support inter-VLAN routing. The switch has several VLANs configured, and hosts in each VLAN need to communicate with hosts in other VLANs. The engineer wants to ensure that the routing process on the switch is efficient and uses the most appropriate Layer 3 forwarding mechanism for directly connected networks. Which mechanism is used by Cisco switches to perform high-speed Layer 3 forwarding between directly connected VLANs?Infrastructure
- 48.A network administrator is configuring a new Cisco router and needs to ensure that all internal hosts can access the internet using a single public IP address. Which NAT configuration type should be implemented?Infrastructure
- 49.A network engineer is configuring a new Layer 3 switch to act as the default gateway for multiple VLANs in a data center. The design requires high availability for the gateway, ensuring that if the primary switch fails, another switch can immediately take over the role without any disruption to client connectivity. Which First Hop Redundancy Protocol (FHRP) is commonly used and provides active-standby redundancy with a virtual IP address and MAC address?Infrastructure
- 50.A network engineer is configuring a new switch in a data center. The switch needs to support high-speed connections and aggregate multiple physical links to increase bandwidth and provide redundancy for connections to a server. Which Layer 2 technology should the engineer implement?Infrastructure