Cisco 300-615 Exam Dumps & Practice Test Questions
Question No 1:
A server is unable to start the operating system after a RAID1 cluster is migrated. The RAID remains inactive both during and after applying the service profile. What step should be taken to fix this issue?
A Configure the SAN boot target in the service profile
B Configure the SAN boot target to any configuration mode
C Use a predefined local disk configuration policy
D Remove the local disk configuration policy
Answer: A
Explanation:
In a server infrastructure that uses SAN-based storage and RAID1 clusters, it's vital to ensure proper boot configurations after a migration. When a server fails to boot from its operating system post-migration, especially if the RAID remains inactive, this strongly indicates a missing or incorrect boot target configuration. The issue likely stems from the service profile not directing the server to the correct storage device for booting.
The service profile is a logical construct that includes definitions for server identity, firmware policies, network settings, and storage configurations. In SAN boot environments, the boot target must explicitly point to the correct LUN on the storage array that contains the bootable operating system. Without this, the server has no way to identify the bootable drive, which results in boot failure and an inactive RAID state.
Choosing option A ensures the service profile is properly configured to include the SAN boot target. Once this target is correctly defined, the system can locate the boot LUN on the SAN, initialize the RAID1 array, and proceed with the boot process. This is a necessary step in SAN environments where the operating system does not reside on local disks but on remote SAN volumes.
Option B is incorrect because simply setting the SAN boot target to “any configuration mode” is vague and ineffective. It doesn't specify the correct LUN or path, which is essential for proper boot operations. The server needs a precise boot target—not just a general or default configuration.
Option C refers to using a predefined local disk configuration policy. This does not apply to this situation since the server is supposed to boot from a SAN, not from a local disk. Applying this policy would likely override the existing SAN setup and introduce further conflicts.
Option D involves removing the local disk configuration policy, which might be irrelevant in this scenario. The issue lies with the SAN target configuration, not the local disk settings. Removing or adjusting local disk policies would not enable the server to find the boot LUN on the SAN.
In summary, configuring the SAN boot target directly within the service profile aligns the boot process with the storage architecture of the system. It activates the RAID1 array, enables detection of the operating system, and resolves the boot failure caused by an undefined or missing boot path in SAN-based environments.
Question No 2:
An engineer notices that the current NPV or NPIV uplink is under heavy network load and wants to add more uplinks to improve traffic distribution. What occurs once these additional uplinks are configured?
A Only new connections automatically use the new uplinks
B Paths must be defined before new connections use the new uplinks
C All connections must be reset before the new uplinks are used
D New and existing connections automatically use the new uplinks
Answer: D
Explanation:
In high-performance computing environments using network virtualization technologies like NPV (Network Port Virtualization) or NPIV (N-Port ID Virtualization), uplinks serve as critical pathways for transmitting data between devices such as switches, servers, and storage systems. When a particular uplink becomes overloaded, adding new uplinks is a common and effective strategy to balance the load and improve performance.
Option D is correct because most modern NPV or NPIV systems are designed with dynamic path management and automatic load balancing. Once the new uplinks are added and properly integrated into the existing fabric, both current and future traffic streams can take advantage of the increased bandwidth. This is achieved without requiring a reboot or reconfiguration of existing sessions, thanks to the fabric's capability to dynamically reassign paths and distribute traffic in real time.
The underlying protocols, such as Fibre Channel or FCoE, inherently support mechanisms like multipathing, which allow multiple physical paths between endpoints. These systems monitor link performance and automatically reroute traffic based on availability and load. As a result, new uplinks are immediately considered by the traffic management algorithm, and both active and idle sessions can be shifted to these new routes to alleviate congestion.
Option A is incorrect because it assumes only new connections will benefit from the added uplinks. In reality, well-configured NPV or NPIV environments will allow ongoing sessions to migrate seamlessly to less congested paths.
Option B is also incorrect because it reflects outdated or overly manual approaches to network configuration. Modern systems do not typically require administrators to manually define paths for each connection to utilize new uplinks. Fabric managers or zoning policies handle path selection dynamically.
Option C incorrectly states that all existing connections need to be reset for the new uplinks to be used. This would be highly disruptive and is contrary to the core design goals of resilient, high-availability network architectures. Enterprise-grade networks are specifically built to handle uplink changes without interrupting active sessions.
In conclusion, adding new uplinks in an NPV or NPIV setup results in immediate benefits for both current and future traffic. The network infrastructure adapts to the new configuration automatically, redistributing the load to maximize throughput and reliability without requiring manual resets or redefinitions. This dynamic capability is essential for maintaining high service availability and performance in complex data center environments.
Question No 3:
An engineer is working to resolve a failure in the Data Center Bridging Exchange (DCBX) negotiation process between a Cisco Nexus switch and a connected server.
What configuration change should the engineer implement to allow DCBX to complete negotiation successfully?
A Enable Enhanced Transmission Selection (ETS)
B Enable Priority Flow Control (PFC)
C Enable Cisco Discovery Protocol (CDP)
D Enable Link Layer Discovery Protocol (LLDP)
Answer: D
Explanation:
DCBX, or Data Center Bridging Exchange, is a protocol that facilitates communication of configuration settings between connected data center devices. These settings include Quality of Service (QoS) features like traffic class definitions, Enhanced Transmission Selection (ETS), and Priority Flow Control (PFC). For DCBX to perform this exchange effectively, it depends on the use of a foundational discovery protocol that allows connected devices to recognize one another and share such information.
The protocol that enables this communication is LLDP, or Link Layer Discovery Protocol. LLDP is an industry-standard protocol that allows devices on a local network to advertise identity and capabilities. In the context of DCBX, LLDP provides the framework through which configuration information can be exchanged. Without LLDP enabled, DCBX cannot operate because it has no underlying mechanism to carry its messages between devices. Therefore, enabling LLDP is essential to allow DCBX negotiation to occur and succeed.
While ETS and PFC are part of the overall Data Center Bridging suite, they are features negotiated through DCBX rather than enablers of the DCBX process itself. Choosing to enable ETS or PFC without enabling LLDP would not resolve a DCBX failure. These features are important once negotiation is successful, but they do not initiate or support the DCBX messaging framework.
CDP, or Cisco Discovery Protocol, is a Cisco proprietary protocol with functionality somewhat similar to LLDP in that it allows Cisco devices to discover each other and exchange information. However, CDP is not used in DCBX exchanges. DCBX specifically relies on LLDP, which is vendor-neutral and supported broadly across many platforms and devices.
Therefore, among all the listed options, enabling LLDP is the correct action. It ensures that both the server and the Nexus switch can participate in the DCBX process, which in turn allows configuration negotiation for traffic management protocols like ETS and PFC. Without LLDP, these negotiations cannot occur, rendering the DCBX exchange inoperative and potentially disrupting network performance.
Question No 4:
A Cisco Nexus switch has placed an interface into an "errdisabled" state and is displaying the error message "DCX-No ACK in 100 PDUs." What is the most likely reason for this condition?
A The host has not responded to the Control Sub-TLV DCBX exchanges of the switch
B The acknowledgement number in the server response has not incremented for 100 exchanges
C Cisco Discovery Protocol (CDP) is disabled on the switch
D Link Layer Discovery Protocol (LLDP) is disabled on the switch
Answer: A
Explanation:
When a Cisco Nexus switch reports the error message "DCX-No ACK in 100 PDUs," it indicates a breakdown in the DCBX, or Data Center Bridging Exchange, communication between the switch and the connected host. This failure is related to the expected acknowledgment of control messages that the switch sends as part of the DCBX negotiation process. DCBX uses these exchanges to configure and agree on traffic management protocols like ETS and PFC.
In the DCBX framework, the switch sends control messages using a format known as TLV, or Type-Length-Value. These messages include critical information about supported QoS features. When the host receives these messages, it is expected to acknowledge them to confirm mutual support and agreement on settings. If no acknowledgment is received for a defined number of messages—in this case, 100—the switch assumes that communication has failed and disables the interface to avoid unstable behavior or misconfiguration.
The primary cause of this issue is the host failing to acknowledge the DCBX control messages. This could happen for several reasons, such as DCBX not being enabled on the host interface, incompatibility, or even a software malfunction that prevents acknowledgment packets from being sent. Because the host does not participate in the exchange, the switch responds by placing the port into an "errdisabled" state to prevent faulty configurations from being applied to a live network environment.
Option B, which refers to the server's acknowledgment number not incrementing, is close in concept but not technically accurate. The problem lies not with the content of acknowledgments, but with their absence altogether. Therefore, it doesn't fully explain why the switch disables the port.
Option C involves CDP, the Cisco Discovery Protocol, which is not relevant to DCBX. DCBX relies on LLDP, and even then, the error in question specifically pertains to the lack of acknowledgment—not the discovery protocol used to initiate communication.
Option D mentions LLDP being disabled, but this does not directly cause the specific "DCX-No ACK" error. While LLDP is necessary for DCBX to operate, if it were disabled, DCBX would not initiate in the first place. The presence of the DCBX error implies LLDP is active, but the host is not replying to the DCBX frames.
Thus, the most accurate explanation is that the host is not responding to the Control Sub-TLV messages sent by the switch, which causes the switch to shut down the interface after failing to receive acknowledgments for 100 consecutive attempts.
Question No 5:
A Fibre Channel interface on a Cisco Nexus 5000 Series Switch is showing bit errors that cause the interface to automatically disable. Before identifying the root cause, a temporary fix is needed to stop the interface from shutting down again.
Which action will prevent the interface from being disabled due to bit errors?
A. Verify that the SFPs are supported.
B. Change the SFP to operate at 4 Gbps instead of 2 Gbps.
C. Run the shutdown and then no shutdown commands on the interface.
D. Run the switchport ignore bit-errors command on the interface.
Answer: D. Run the switchport ignore bit-errors command on the interface.
Explanation:
In Fibre Channel environments, bit errors on an interface can interrupt communication and cause the switch to disable the interface to protect the network. The Cisco Nexus 5000 Series Switch uses Fibre Channel interfaces for SAN connectivity, which requires error-free data transmission. When bit errors occur, the interface shuts down automatically to avoid further disruption.
To temporarily stop the interface from disabling while investigating the root cause, applying the switchport ignore bit-errors command is effective. This command tells the switch to overlook bit errors and keep the interface operational despite the errors. While this does not fix the root cause, it allows the interface to remain active for troubleshooting or temporary use.
Looking at each option:
A. Verifying SFP support is important for performance but won’t stop the interface from disabling due to bit errors immediately. It helps identify long-term fixes, not temporary workarounds.
B. Changing the SFP speed to 4 Gbps may not help if bit errors already exist, and mismatched speeds can cause further errors. This is not a quick solution unless speed mismatch is the known cause.
C. Running shutdown and no shutdown commands can reset the interface but does not prevent it from disabling again if bit errors persist.
D. The switchport ignore bit-errors command directly prevents automatic interface shutdown by instructing the switch to ignore bit errors, making it the best temporary workaround while the root cause is investigated.
In summary, running the switchport ignore bit-errors command is the most effective temporary solution to keep the interface active despite bit errors. However, the underlying issues such as hardware faults, interference, or misconfiguration should be diagnosed and resolved for a permanent fix.
Question No 6:
A fabric interconnect fails to boot and shows the loader prompt on the console. Which two steps should be taken to fix this problem? (Choose two.)
A. Load an uncorrupted bootloader image.
B. Load an uncorrupted kickstart image.
C. Reconnect Layer 1 and Layer 2 cables between the fabric interconnects.
D. Reformat the fabric interconnect.
E. Load the correct version of the boot image.
Answer:
A. Load an uncorrupted bootloader image.
E. Load the correct version of the boot image.
Explanation:
When a fabric interconnect fails to start and shows the loader prompt, it usually means it cannot find or load the necessary software to boot fully. To resolve this, two main steps are needed:
A. Loading an uncorrupted bootloader image is essential because the bootloader initializes hardware and loads the operating system. If corrupted, the system will fail to boot. Replacing it with a good version restores this function.
E. Loading the correct boot image version is also critical since the fabric interconnect needs a compatible operating system image to start. Missing or incompatible images will cause boot failure. Specifying the correct image through the loader prompt allows the boot process to continue.
Why the other options are incorrect:
B. The kickstart image is important for Cisco UCS systems but won’t help if the system can’t load the bootloader or boot image. It is used later in the boot process.
C. Reconnecting Layer 1 and Layer 2 cables may fix connectivity issues but will not resolve a failure to boot and the presence of the loader prompt, which is a software loading problem.
D. Reformatting the fabric interconnect is a last resort that wipes configurations. It’s not usually necessary for bootloader or boot image issues and should be avoided until other options are exhausted.
Therefore, addressing the bootloader and boot image problems directly usually resolves this boot failure without drastic measures or hardware reconnections.
Question No 7:
What mechanism does Cisco TrustSec primarily utilize to implement security policies and segment network traffic effectively?
A MACsec encryption
B IPsec tunnels
C Security Group Tags (SGTs)
D Transport Layer Security (TLS)
Answer: C
Explanation:
Cisco TrustSec relies on Security Group Tags (SGTs) to enforce security policies and segment traffic within a network. Unlike traditional methods that depend on IP addresses or VLANs, TrustSec assigns SGTs to users or devices, reflecting their security role or group. These tags are embedded in packet headers and recognized throughout the network infrastructure, enabling dynamic and scalable policy enforcement. This method simplifies network segmentation, improves security posture, and allows granular access control without the complexity of maintaining numerous VLANs or IP-based rules. In contrast, MACsec (A) provides link-layer encryption but does not facilitate segmentation; IPsec (B) secures data in transit but is not used for tagging; TLS (D) encrypts data at the transport layer but does not handle access control through tagging.
Question No 8:
How does Cisco SD-Access facilitate simplified network segmentation and security enforcement?
A Through VLAN isolation
B By using Security Group Tags (SGTs)
C Via Access Control Lists (ACLs)
D With port-based authentication
Answer: B
Explanation:
Cisco SD-Access simplifies segmentation by employing Security Group Tags (SGTs), which logically group users and devices according to roles rather than physical location or IP subnets. This tagging allows the network to enforce consistent policies regardless of device movement, providing both flexibility and security. Traditional methods such as VLAN isolation (A) and ACL filtering (C) are more static and complex to manage at scale. Port-based authentication (D) can control initial access but lacks the ongoing policy enforcement capabilities provided by SGTs in SD-Access. SGT-based segmentation ensures scalable, dynamic, and role-based security policies that adapt with the network environment.
Question No 9:
In the Cisco TrustSec model, which method is used to transport user identity information across network devices?
A Embedding credentials in packet payloads
B Tagging packets with Security Group Tags (SGTs)
C Filtering by MAC addresses
D Encrypting packets using IPsec
Answer: B
Explanation:
Within Cisco TrustSec, user identity is conveyed by appending Security Group Tags (SGTs) to network packets. These tags represent user or device security roles, enabling devices to enforce appropriate access policies without relying solely on IP addresses. Embedding credentials in packet payloads (A) would expose sensitive data and is not scalable. MAC address filtering (C) provides limited security and is easily spoofed. IPsec encryption (D) protects data integrity and confidentiality but does not communicate identity. The use of SGTs creates a more secure, scalable, and policy-driven approach to network access control.
Question No 10:
Which Cisco technology works alongside TrustSec to provide hardware-accelerated encryption on Ethernet links?
A Cisco DNA Center
B MACsec (Media Access Control Security)
C NetFlow Traffic Analysis
D Cisco AnyConnect VPN
Answer: B
Explanation:
MACsec (Media Access Control Security) integrates with Cisco TrustSec to deliver hardware-based encryption at Layer 2, securing data between directly connected devices. MACsec protects against attacks such as eavesdropping or man-in-the-middle by encrypting Ethernet frames, ensuring confidentiality and integrity of data on local links. Cisco DNA Center (A) manages network devices but does not perform encryption. NetFlow (C) is for traffic analysis and monitoring. Cisco AnyConnect (D) is a client VPN solution for remote users, providing encryption but not hardware-based link security. MACsec complements TrustSec’s policy enforcement by securing data in transit on Ethernet connections.
