CiscoProfessional level300-445Page 3 of 3

300-445 exam dumps: questions 201 to 254 of 254

Page 3 of the free 300-445 question bank for the Designing and Implementing Enterprise Network Assurance exam. Questions 201 to 254 are listed below, the first 5 in full with answers and explanations. Back to page 1 for the exam overview and FAQ.

Question bank last updated February 2025

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Questions 201 to 205 of 254

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300-445 Question 201

Select 4

An enterprise network is experiencing intermittent connectivity issues and degraded performance across multiple sites. After analyzing the traffic, you identify abnormal routing behavior and suspect a security issue. Which of the following could be the most likely causes of this issue?

A
BGP hijacking, where malicious actors advertise incorrect routes to reroute traffic
B
DNS hijacking, where DNS queries are redirected to malicious servers
C
DDoS attacks targeting critical network infrastructure and saturating bandwidth
D
Route leaking, where internal routes are accidentally or maliciously shared with external networks
E
Misconfigured VLANs causing broadcast storms within the network

Show answer and explanation

Correct answers: A, B, C, D

Explanation

Enterprise network performance can be affected by various security issues. BGP hijacking, DNS hijacking, DDoS attacks, and route leaking are all security-related problems that can degrade network performance by disrupting normal routing, overwhelming resources, or redirecting traffic. Misconfigured VLANs, while a potential network issue, are not security issues and do not align with the context of the question.

A. Correct.
BGP hijacking can lead to traffic being rerouted through unintended paths, which introduces latency, packet loss, and potential data interception, directly impacting network performance.
B. Correct.
DNS hijacking redirects DNS queries to malicious servers, which can result in users being directed to incorrect or malicious destinations, affecting both performance and security.
C. Correct.
DDoS attacks can overwhelm network infrastructure with excessive traffic, causing degraded performance and connectivity issues.
D. Correct.
Route leaking exposes internal routes to external networks, leading to inefficient routing and potential security risks, which can degrade network performance.
E. Incorrect.
While misconfigured VLANs can cause broadcast storms and local network issues, this is not a security issue tied to attacks like DDoS, DNS hijacking, or BGP hijacking.

300-445 Question 202

Single answer

While monitoring your enterprise network, you notice unusually high latency and packet loss across multiple critical services. Upon further investigation, you identify that traffic destined for your servers is being redirected to unknown IP addresses. Which type of attack is MOST LIKELY occurring, and what should you analyze to confirm the issue?

A
DDoS attack; analyze traffic patterns for a sudden spike in requests to your servers
B
DNS hijacking; investigate DNS resolution logs to check if legitimate domain queries are being redirected
C
BGP hijacking; review BGP route advertisements to detect unauthorized changes in prefix announcements
D
Route leaking; analyze routing tables to identify if private prefixes are improperly advertised to external peers

Show answer and explanation

Correct answer: C

Explanation

The symptoms described, high latency, packet loss, and redirection of traffic, are indicative of BGP hijacking, where malicious actors manipulate BGP advertisements to reroute traffic to unauthorized IP addresses. Analyzing BGP route advertisements for unauthorized changes is critical to confirming this type of attack.

A. Incorrect.
DDoS attacks typically overwhelm servers with a flood of traffic, causing resource exhaustion. However, this scenario describes traffic being redirected to unknown IPs, which does not align with the characteristics of a DDoS attack.
B. Incorrect.
DNS hijacking involves altering DNS resolution to redirect legitimate domain queries to malicious sites. While similar in outcome, the problem here is related to routing rather than DNS resolution.
C. Correct.
BGP hijacking occurs when an unauthorized entity advertises IP prefixes that it does not own, causing traffic meant for legitimate destinations to be redirected. This matches the scenario described, where traffic is redirected to unknown IPs.
D. Incorrect.
Route leaking involves the improper advertisement of internal routes to external networks, which can lead to routing inefficiencies or data exposure. However, it does not specifically explain the redirection of traffic to unknown IPs as described in the scenario.

300-445 Question 203

Single answer

Your organization has experienced sudden performance degradation in its network, including significant packet loss and increased latency. Upon investigation, you discover that traffic destined for your network is being rerouted through unfamiliar autonomous systems (ASes), leading to potential traffic interception and disruption. Which network security issue is most likely causing this problem?

A
DDoS attack
B
DNS hijacking
C
BGP hijacking
D
Route leaking

Show answer and explanation

Correct answer: C

Explanation

The symptoms described in the scenario, including traffic being rerouted through unfamiliar autonomous systems and potential interception, are indicative of a BGP hijacking attack. BGP hijacking exploits the trust-based nature of the Border Gateway Protocol, allowing attackers to announce fraudulent routes. This can lead to significant performance degradation, interception of data, and potential security breaches.

A. Incorrect.
DDoS attacks overwhelm a network or service with excessive traffic, causing denial of service. However, they do not involve rerouting traffic through unauthorized ASes.
B. Incorrect.
DNS hijacking involves redirecting domain name requests to malicious servers, which could cause service interruptions or compromise user data. This does not pertain to rerouting traffic through unauthorized autonomous systems.
C. Correct.
BGP hijacking occurs when an attacker announces incorrect routes using the Border Gateway Protocol (BGP), causing traffic to be misrouted through unauthorized networks. This matches the described symptoms of traffic interception and disruption.
D. Incorrect.
Route leaking involves the improper advertisement of routes between ASes, which might lead to suboptimal routing but does not specifically align with the described traffic interception scenario.

300-445 Question 204

Single answer

An enterprise network is experiencing intermittent connectivity issues and degraded performance. Upon investigation, you observe that certain IP prefixes originally belonging to the organization are being advertised from an unauthorized source. What could be the most likely cause of this issue?

A
DDoS attack overwhelming the network infrastructure
B
BGP hijacking by a malicious actor
C
DNS hijacking redirecting traffic to malicious domains
D
Route leaking by a misconfigured or malicious third-party network

Show answer and explanation

Correct answer: B

Explanation

The issue described in the scenario, unauthorized advertisement of IP prefixes, is characteristic of BGP hijacking. This occurs when a malicious actor or misconfiguration causes incorrect routing advertisements, leading to traffic being misrouted or intercepted. Understanding how BGP hijacking impacts network performance is critical for ensuring enterprise network assurance.

A. Incorrect.
A DDoS attack involves overwhelming a network with traffic but does not involve unauthorized advertisement of IP prefixes. This is not relevant to the scenario.
B. Correct.
BGP hijacking occurs when a malicious actor advertises IP prefixes not belonging to them, causing traffic to be misrouted. This matches the described issue.
C. Incorrect.
DNS hijacking involves redirecting DNS resolution to malicious servers. While it can affect network performance, it does not align with the unauthorized advertisement of IP prefixes.
D. Incorrect.
Route leaking involves the unintended redistribution of routing information, which can cause connectivity issues, but it is not the same as unauthorized prefix advertisement.

300-445 Question 205

Select 3

A multinational enterprise has been experiencing intermittent network disruptions and degraded performance. Upon analysis, the network team suspects multiple security issues affecting the network. Which of the following actions would help identify and mitigate the threats of DNS hijacking and BGP hijacking?

A
Enable RPKI (Resource Public Key Infrastructure) to validate BGP routes.
B
Implement DNSSEC to secure DNS queries and responses.
C
Monitor network traffic for unusual spikes indicative of DDoS attacks.
D
Configure rate-limiting on edge routers to prevent route leaking.
E
Use prefix filtering to ensure only authorized prefixes are advertised.

Show answer and explanation

Correct answers: A, B, E

Explanation

DNS hijacking and BGP hijacking are critical security threats that can significantly impact network performance and availability. Enabling RPKI and implementing DNSSEC are specific measures that directly address these issues by securing BGP route validation and DNS queries, respectively. Additionally, prefix filtering ensures that unauthorized prefixes are not advertised, reducing the risk of route leaks and BGP hijacking. These measures together help secure the enterprise network against these threats.

A. Correct.
RPKI (Resource Public Key Infrastructure) is a security framework that helps prevent BGP hijacking by validating the origination of BGP routes, ensuring that only authorized entities can advertise specific IP prefixes.
B. Correct.
DNSSEC (Domain Name System Security Extensions) adds a layer of security to DNS by enabling validation of DNS responses, effectively mitigating DNS hijacking threats.
C. Incorrect.
While monitoring traffic for unusual spikes is useful for detecting DDoS attacks, it is not directly applicable for identifying or mitigating DNS hijacking or BGP hijacking.
D. Incorrect.
Rate-limiting on edge routers is a mitigation technique for controlling traffic flow and preventing DDoS attacks but does not directly address route leaking or hijacking.
E. Correct.
Prefix filtering ensures that only authorized prefixes are advertised and accepted, making it an effective method to prevent route leaks and mitigate BGP hijacking.

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300-445 practice questions 201 to 254 of 254

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