Cisco 300-415 Practice Test Questions, Exam Dumps

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300-415 Cisco Practice Test Questions and Exam Dumps

Question No 1:

In a Cisco SD-WAN architecture, which component is responsible for managing the control plane of the overlay network, ensuring the establishment, adjustment, and maintenance of connections between the WAN Edge devices that form the SD-WAN fabric?

A. APIC-EM
B. vSmart
C. vManage
D. vBond

Answer:

The correct answer is B. vSmart.

Explanation:

In a Cisco SD-WAN (Software-Defined Wide Area Network) architecture, the control plane is crucial for establishing, adjusting, and maintaining secure and efficient connections between all the devices in the SD-WAN fabric. The Cisco SD-WAN fabric is made up of several key components, each responsible for different functions. The component that specifically manages the control plane is vSmart.

vSmart is the central control plane orchestrator in Cisco SD-WAN. It is responsible for distributing and managing routing information across the SD-WAN fabric. The vSmart controller is involved in the process of creating and maintaining the overlay network by establishing secure communication tunnels (data plane) between the WAN Edge devices (routers). It is also responsible for policy enforcement, path selection, and segmenting the network into different policies, ensuring that the network behaves as per the desired configuration. vSmart handles dynamic routing protocols (such as OMP - Overlay Management Protocol) and also manages the communication between vBond, vManage, and the WAN Edge devices.

To break it down further:

vSmart: Manages the control plane, distributing routing information, enforcing policies, and ensuring that the overlay network topology is consistently maintained. This component ensures that all WAN Edge devices are able to communicate securely and in an optimized manner.
vBond: Responsible for the initial authentication and secure tunneling of devices in the SD-WAN fabric. It validates the identities of devices (like vManage and vSmart), ensuring that only trusted devices can join the SD-WAN.
vManage: Focuses on network management and monitoring. It provides a centralized dashboard for configuration, monitoring, and troubleshooting of the entire SD-WAN network, but it doesn't manage the control plane directly.
APIC-EM: APIC-EM (Application Policy Infrastructure Controller-Enterprise Module) is an earlier Cisco network management solution but is not a core part of Cisco SD-WAN.

Thus, vSmart plays a central role in overseeing the control plane and is critical for the proper operation of Cisco SD-WAN, enabling the configuration and maintenance of connections across WAN Edge devices.

Question No 2:

Which two hardware platforms are compatible with Cisco IOS XE SD-WAN images for running SD-WAN functionality? (Choose two.)

A. ISR4000 series
B. ISR9300 series
C. vEdge-1000 series
D. ASR9000 series
E. ASR1000 series

Answer:

The correct answers are A. ISR4000 series and E. ASR1000 series.

Explanation:

Cisco's SD-WAN solution leverages software-defined networking principles to enable a more flexible, secure, and efficient WAN infrastructure. As part of this solution, Cisco uses the IOS XE operating system to deploy SD-WAN functionality on specific hardware platforms. In this context, not all hardware platforms are designed to support Cisco's IOS XE SD-WAN images. Let’s look at the two platforms that support these images and why.

1. ISR4000 Series (Answer A):
The ISR4000 series is one of the key platforms that supports Cisco IOS XE SD-WAN images. The ISR (Integrated Services Routers) 4000 series offers advanced routing and security features designed for branch offices, and it’s widely used for deploying SD-WAN solutions. These routers provide enhanced performance, scalability, and a modular design, allowing for a variety of network services to be delivered via the IOS XE platform. They support SD-WAN through the integration of Cisco’s SD-WAN software features, including routing, security, and management capabilities. The ISR4000 series routers are designed to handle the full SD-WAN architecture, from data plane to control plane, making them ideal for SD-WAN deployment in distributed environments.

2. ASR1000 Series (Answer E):
The ASR1000 series is another hardware platform that supports Cisco IOS XE SD-WAN images. The ASR (Aggregation Services Router) 1000 series is designed for higher performance and larger-scale deployments. It is typically used in enterprise WANs, service provider environments, and large-scale branch or data center deployments. These routers provide high availability, flexibility, and scalability, essential for SD-WAN solutions that require robust performance across a large enterprise or multi-location network. The ASR1000 series routers support IOS XE, which integrates seamlessly with Cisco SD-WAN to offer secure, automated, and policy-based routing for traffic across the SD-WAN fabric.

Platforms Not Supported:

ISR9300 Series (Answer B): While the ISR9300 series provides powerful capabilities, it is typically not listed as a platform supporting IOS XE SD-WAN images. This series is more focused on specific service provider and high-performance environments.
vEdge-1000 Series (Answer C): The vEdge routers are part of Cisco’s previous SD-WAN architecture (pre-IOS XE). These are not compatible with Cisco IOS XE SD-WAN images.
ASR9000 Series (Answer D): The ASR9000 is a service provider router used for core routing and high-speed services but does not natively support the IOS XE SD-WAN images.

In conclusion, ISR4000 and ASR1000 are the two hardware platforms that support Cisco IOS XE SD-WAN images, providing the foundation for efficient SD-WAN operations in various enterprise network environments.

Question No 3:

What is the default protocol used for control plane connections in a Cisco SD-WAN network to ensure secure communication between devices?

A. HTTPS
B. TLS
C. IPsec
D. DTLS

Answer:

The correct answer is D. DTLS.

Explanation:

In a Cisco SD-WAN environment, ensuring the security of control plane communication between devices is essential for maintaining the integrity and reliability of the SD-WAN fabric. The control plane manages the exchange of routing information, policy distribution, and the overall orchestration of the SD-WAN fabric. For secure communication of this data, Cisco SD-WAN uses DTLS (Datagram Transport Layer Security) as the default protocol for control plane connections.

DTLS (Datagram Transport Layer Security) is the protocol used to secure the control plane in Cisco SD-WAN for several reasons:

Low Latency and Performance: DTLS is designed to provide security for datagram-based protocols like UDP (User Datagram Protocol). UDP is commonly used in real-time applications, such as voice and video, where low latency is crucial. Unlike TCP, which involves connection establishment and stateful communication, DTLS works over UDP, allowing for faster and more efficient connections, which is essential in high-performance SD-WAN deployments.
Encryption and Integrity: DTLS provides strong encryption and integrity protection for the data exchanged between devices. This ensures that sensitive information, such as routing updates and security policies, is securely transmitted without interception or tampering.
Support for Unreliable Transport: As DTLS is built to secure UDP traffic, it handles packet loss and retransmission gracefully, which is beneficial for SD-WAN environments where networks might experience varying levels of reliability. By securing UDP traffic, DTLS helps maintain the stability and security of control plane communications even when there are issues with the underlying transport layer.

While IPsec (Internet Protocol Security) is widely used to secure the data plane (carrying user traffic), DTLS is the default for securing control plane communications in Cisco SD-WAN. This protocol enables the secure exchange of control information between key devices in the SD-WAN architecture, such as vSmart controllers, WAN Edge devices, and vBond, without the overhead associated with TCP-based protocols.

Other Options:

HTTPS (A): Typically used for securing web-based applications but not ideal for control plane communication in SD-WAN.
TLS (B): While similar to DTLS, TLS is designed for TCP connections, which is not the optimal choice for control plane traffic in Cisco SD-WAN.
IPsec (C): Primarily used for securing the data plane and end-to-end encryption of user traffic rather than control plane connections.

Thus, DTLS is the default protocol for securing control plane connections in Cisco SD-WAN, ensuring efficient, low-latency, and encrypted communication between devices in the network.

Question No 4:

Which component of the Cisco SD-WAN control plane architecture is designed to be located in a public internet address space and facilitates NAT traversal for devices in the SD-WAN fabric?

A. WAN Edge
B. vSmart
C. vBond
D. vManage

Answer:

The correct answer is C. vBond.

Explanation:

In the Cisco SD-WAN architecture, vBond plays a critical role in facilitating secure and reliable communication between various devices in the SD-WAN fabric, particularly in environments where NAT (Network Address Translation) is involved. vBond is the component that is specifically designed to be located in a public internet address space and handles NAT traversal, ensuring that devices behind NAT devices or firewalls can still securely communicate with each other.

Let’s break down the role of vBond and why it’s crucial for NAT traversal:

vBond:

Public Internet Address: vBond is typically deployed with a public IP address, meaning it is accessible from any location via the internet. This allows vBond to act as a central point of trust and authentication for all devices within the SD-WAN fabric, regardless of whether the devices are behind a NAT or firewall.
Facilitates NAT Traversal: When devices (such as WAN Edge routers or controllers) are behind NAT devices, they cannot always directly initiate a connection to another device due to the private IP address assigned by the NAT. vBond helps by facilitating the initial handshake and authentication between devices. It allows these devices to establish a secure tunnel even if they are behind NAT or firewalls, solving the issue of restricted IP connectivity.
Authentication and Secure Connectivity: In addition to enabling NAT traversal, vBond serves as the initial point of authentication in the SD-WAN architecture. All devices, including vSmart and WAN Edge routers, must authenticate themselves with vBond before joining the SD-WAN fabric, ensuring that only trusted devices are part of the network.

Other Components:

WAN Edge (A): These devices are located at the network edges (branch offices, data centers), and while they may be behind NAT, they rely on vBond to facilitate the initial connection. They do not facilitate NAT traversal themselves.
vSmart (B): vSmart is the central controller for the SD-WAN control plane that manages routing and policy. However, it does not have the role of facilitating NAT traversal. It communicates with other devices through secure tunnels but relies on vBond for the initial connection.
vManage (D): vManage is used for monitoring, management, and orchestration of the SD-WAN network. It does not play a role in facilitating NAT traversal or being accessible from a public IP space for this purpose.

Thus, vBond is the component responsible for being placed in a public IP space and facilitating NAT traversal, making it a critical element in establishing secure and reliable connections in Cisco SD-WAN.

Question No 5:

Which Cisco SD-WAN WAN Edge platform is designed to support both LTE and Wi-Fi connectivity for wide area network (WAN) access?

A. ISR 1101
B. ASR 1001
C. CSR 1000v
D. vEdge 2000

Answer:

The correct answer is A. ISR 1101.

Explanation:

In the context of Cisco SD-WAN, WAN Edge platforms are devices deployed at the edge of a network to provide secure connectivity between branch offices, data centers, and remote sites. These platforms are responsible for connecting to the SD-WAN fabric, handling routing, security, and managing traffic across the network. One of the important factors to consider when selecting a WAN Edge platform is the type of connectivity options it supports.

Cisco ISR 1101 is a versatile platform that supports LTE (Long Term Evolution) and Wi-Fi connectivity, making it a suitable choice for environments where WAN connectivity needs to be flexible and mobile. This is particularly important for remote sites or branch offices where traditional wired connectivity options might not be available, or where flexibility in connectivity is required for continuous network access.

Here’s why the ISR 1101 is the correct choice:

LTE Support: The ISR 1101 comes with built-in support for LTE, allowing the device to use cellular networks for internet access and data communication. This is especially useful in remote or mobile environments where traditional wired WAN connections (e.g., DSL, fiber) are unavailable, or as a failover solution in case the primary WAN link fails.
Wi-Fi Support: The ISR 1101 also supports Wi-Fi, enabling wireless access for connected devices and making it a good fit for branch offices, small businesses, or temporary installations that require wireless connectivity as part of their SD-WAN deployment. This flexibility helps reduce the dependency on wired WAN links and allows easier setup and maintenance in varied environments.

Other Options:

ASR 1001 (B): The ASR 1001 is a high-performance router designed for larger-scale deployments. It does not support LTE or Wi-Fi natively, as it is focused on traditional wired network environments for more robust enterprise or service provider needs.
CSR 1000v (C): The CSR 1000v is a virtual router that provides WAN services in virtualized environments, such as cloud deployments. It does not have physical LTE or Wi-Fi interfaces, as it operates in virtualized data centers or cloud environments.
vEdge 2000 (D): The vEdge 2000 is part of Cisco's legacy SD-WAN platform. While it is a powerful edge device, it does not support LTE or Wi-Fi connectivity directly. Instead, it is intended for enterprise deployments that use traditional broadband or MPLS connections.

Therefore, the ISR 1101 is the Cisco SD-WAN WAN Edge platform that provides LTE and Wi-Fi support, making it an excellent choice for environments requiring flexibility in connectivity, especially where mobile or wireless access is necessary.

Question No 6:

Refer to the exhibit. In the context of a Bidirectional Forwarding Detection (BFD) session, what does the value of 8 represent?

A. Dead timer of the BFD session
B. Poll interval of the BFD session
C. Hello timer of the BFD session
D. Number of BFD sessions

Answer:

The correct answer is B. Poll interval of the BFD session.

Explanation:

Bidirectional Forwarding Detection (BFD) is a protocol used in networking to quickly detect failures in the path between two devices. It is typically used in scenarios where high availability and fast failover are required, such as in routing protocols like OSPF, BGP, and MPLS. BFD is a lightweight, rapid detection mechanism that operates at the data link layer and provides a fast mechanism to detect failures in the forwarding path.

The BFD session parameters are critical to understanding how quickly the network can respond to a failure. Among these parameters are timers that define how often BFD messages are exchanged and how long the devices will wait before considering a session to be down.

In the context of the question, the value of 8 represents the poll interval of the BFD session. The poll interval refers to the time between BFD control packets that are sent to detect failures. A smaller poll interval means more frequent checks and faster failure detection, while a larger poll interval may reduce the overhead but also increase the time taken to detect a failure.

Here’s an explanation of each option:

A. Dead timer of the BFD session: The dead timer specifies how long to wait after not receiving a BFD control packet before declaring the session down. This timer is typically larger than the poll interval and is not represented by the value of 8 in this case.
B. Poll interval of the BFD session (Correct Answer): The poll interval defines how often the BFD packets are sent between devices to check the path's status. In this case, the value 8 represents the interval between these poll packets in milliseconds.
C. Hello timer of the BFD session: The hello timer is another type of timer used in other protocols like OSPF or EIGRP, but it is not directly related to BFD. It refers to how often "hello" messages are sent to establish and maintain neighbor relationships.
D. Number of BFD sessions: This option is incorrect because the value of 8 does not represent the number of BFD sessions. BFD sessions are typically established per interface or per routing neighbor, not represented by a numeric value like this.

Thus, B. Poll interval is the correct answer because the value 8 specifically refers to the frequency of BFD control packets being sent to detect failures, which is a key part of the BFD mechanism for fast failure detection in routing and network protocols.

Question No 7:

When a network administrator brings up a new WAN Edge router for branch connectivity in a Cisco SD-WAN environment, which types of tunnels are established when the router connects to the SD-WAN fabric?

A. DTLS or TLS tunnel with vSmart controller and IPsec tunnel with vBond controller
B. DTLS or TLS tunnel with vBond controller and IPsec tunnel with vManage controller
C. DTLS or TLS tunnel with vBond controller and IPsec tunnel with other WAN Edge routers
D. DTLS or TLS tunnel with vSmart controller and IPsec tunnel with other WAN Edge routers

Answer:

The correct answer is A. DTLS or TLS tunnel with vSmart controller and IPsec tunnel with vBond controller.

Explanation:

In a Cisco SD-WAN architecture, when a new WAN Edge router is brought up to establish branch connectivity, it interacts with several key components of the SD-WAN fabric, including the vBond, vSmart, and vManage controllers. These controllers are responsible for managing various aspects of SD-WAN operation, including authentication, routing, policy distribution, and network management.

When the WAN Edge router first connects to the SD-WAN fabric, it establishes two key types of tunnels:

DTLS or TLS Tunnel with vBond:
The vBond controller is responsible for the initial authentication of the WAN Edge router. The connection between the WAN Edge router and vBond is established using DTLS (Datagram Transport Layer Security) or TLS (Transport Layer Security). The use of DTLS or TLS ensures that the communication is secure and that both the WAN Edge router and vBond controller can authenticate each other. The vBond acts as a trust anchor, allowing the WAN Edge device to join the SD-WAN fabric securely. Once authenticated, the vBond controller also facilitates the exchange of information necessary for the establishment of additional tunnels with other components in the fabric (like the vSmart controller and other WAN Edge routers).
IPsec Tunnel with vSmart or Other WAN Edge Routers:
Once the initial secure connection to vBond is established, the WAN Edge router will then create an IPsec tunnel with the vSmart controller or with other WAN Edge routers, depending on the configuration. The vSmart controller manages the SD-WAN control plane, responsible for distributing routing information and policies. The IPsec tunnel provides a secure, encrypted communication channel between WAN Edge devices and the vSmart controller. This ensures the integrity and confidentiality of control plane traffic, including routing and policy information.

Other Options:

B. DTLS or TLS tunnel with vBond controller and IPsec tunnel with vManage controller:
This option is incorrect because vManage handles network management and orchestration, not IPsec tunneling for communication between WAN Edge routers.
C. DTLS or TLS tunnel with vBond controller and IPsec tunnel with other WAN Edge routers:
While IPsec tunnels are established between WAN Edge routers, the vSmart controller, not other WAN Edge routers, manages the control plane. This option is partially correct but does not capture the role of vSmart.
D. DTLS or TLS tunnel with vSmart controller and IPsec tunnel with other WAN Edge routers:
This option is incorrect because the initial connection from the WAN Edge router is made with vBond, not vSmart. vSmart is used for control plane communication after the vBond authentication.

The correct answer is A because the WAN Edge router first establishes a DTLS or TLS tunnel with vBond for authentication, and then an IPsec tunnel with the vSmart controller or other WAN Edge routers for control and data plane communication in the SD-WAN fabric.

Question No 8:

In a Cisco SD-WAN environment, if Smart Account Sync is not used, which component is responsible for uploading an authorized serial number file?

A. WAN Edge
B. vSmart
C. vBond
D. vManage

Answer:

The correct answer is D. vManage.

Explanation:

In a Cisco SD-WAN deployment, devices such as WAN Edge routers, vSmart controllers, vBond controllers, and vManage play essential roles in the operation and management of the SD-WAN fabric. Each of these components is responsible for specific tasks, and understanding their functions is important when setting up and configuring the SD-WAN solution.

One important part of the initial configuration involves authenticating and registering devices within the SD-WAN fabric. This process typically requires the use of serial numbers associated with the hardware devices. These serial numbers are required to be authorized before the devices can be successfully integrated into the SD-WAN network.

In Cisco SD-WAN, there are two ways to register and authorize devices: through Smart Account Sync (which automatically syncs authorized serial numbers) or manually by uploading an authorized serial number file. When Smart Account Sync is not used, the serial number file needs to be manually uploaded to the Cisco SD-WAN system.

In this case, vManage is the component responsible for uploading and managing the serial number file. Here's why:

vManage:
vManage is the central network management and orchestration platform in Cisco SD-WAN. It provides a graphical interface for administrators to configure, monitor, and maintain the SD-WAN network. In the context of onboarding devices, vManage is where the authorized serial number file is uploaded. This file contains the serial numbers of the devices (e.g., WAN Edge routers, vBond, vSmart) that need to be registered and authenticated within the SD-WAN fabric. After uploading the file, vManage ensures that the devices are properly authorized to join the SD-WAN network.
Other Options:

WAN Edge (A): The WAN Edge router is a network device that connects to the SD-WAN fabric. While it is an essential part of the SD-WAN, it is not responsible for uploading serial number files. Its primary function is to forward data and handle secure communication with other devices in the SD-WAN.
vSmart (B): The vSmart controller is responsible for the control plane of the SD-WAN, including policy distribution and routing. It does not handle the uploading or management of serial number files.
vBond (C): The vBond controller is responsible for initial authentication and establishing secure connections between the devices in the SD-WAN fabric. It ensures that only authorized devices can join the fabric, but the actual process of uploading serial numbers is done in vManage, not vBond.

When Smart Account Sync is not used, the vManage component is responsible for uploading the authorized serial number file. This ensures that devices are registered and authenticated correctly, allowing them to join the SD-WAN fabric and function as part of the network.

Question No 9:

What is the default port used for vBond under controller certificates in a Cisco SD-WAN environment if no alternate port is configured?

A. 12344
B. 12345
C. 12347
D. 12346

Answer:

The correct answer is D. 12346.

Explanation:

In a Cisco SD-WAN architecture, the vBond controller is responsible for the initial authentication and secure establishment of communication between SD-WAN devices (such as vSmart controllers and WAN Edge routers). It plays a key role in ensuring that devices joining the SD-WAN fabric are trusted and authorized to participate in the network.

The controller certificates are used to authenticate the communication between the vBond and other devices within the SD-WAN fabric. When devices (such as WAN Edge routers or vSmart controllers) first attempt to join the network, they must authenticate with vBond over a specific port that is dedicated to this purpose.

The default port used by the vBond controller for the controller certificate exchange (if no alternate port is configured) is 12346. This port is reserved for the secure communication required to establish the initial connection between SD-WAN devices and vBond.

Here's a breakdown of how it works:

vBond Communication: When a new device (like a WAN Edge router) is brought up in the SD-WAN network, it needs to establish a secure connection with the vBond controller to authenticate and register itself. The device will attempt to reach vBond using the default port, 12346.
Controller Certificate Exchange: The vBond controller uses this port to exchange certificates and authenticate the WAN Edge router. This authentication is a critical step in ensuring that only authorized devices are allowed to join the SD-WAN fabric. Once authenticated, the vBond controller facilitates the setup of other necessary tunnels for secure communication within the SD-WAN fabric.
Alternate Port Configuration: If an administrator needs to configure a different port for vBond communication (for reasons such as security or network configuration), this can be done through the SD-WAN configuration. However, unless specified otherwise, port 12346 is the default port for this purpose.

Other Options:

A. 12344: This is not the correct port for vBond controller communication.
B. 12345: Similar to 12344, this is not used for vBond communication.
C. 12347: While it may be a valid port for other purposes, it is not the default port for vBond controller certificates.

The default port used for vBond under controller certificates, if no alternate port is configured, is 12346. This port is critical for the secure initial communication and authentication process that occurs when new devices join the Cisco SD-WAN fabric.