350-701 Exam Dumps - Cisco CCNP Security Questions and Answers

ExplanationDomain name system (DNS) is the protocol that translates human-friendly URLs, such as securitytut.com, into IP addresses, such as 183.33.24.13. Because DNS messages are only used as the beginning of each communication and they are not intended for data transfer, many organizations do not monitor their DNS traffic for malicious activity. As a result, DNS-based attacks can be effective if launched against their networks. DNS tunneling is one such attack.An example of DNS Tunneling is shown below:

• The attacker incorporates one of many open-source DNS tunneling kits into an authoritative DNSnameserver (NS) and malicious payload.2. An IP address (e.g. 1.2.3.4) is allocated from the attacker’s infrastructure and a domain name (e.g. attackerdomain.com) is registered or reused. The registrar informs the top-level domain (.com) nameservers to refer requests for attackerdomain.com to ns.attackerdomain.com, which has a DNS record mapped to 1.2.3.43. The attacker compromises a system with the malicious payload. Once the desired data is obtained, the payload encodes the data as a series of 32 characters (0-9, A-Z) broken into short strings (3KJ242AIE9, P028X977W,…).4. The payload initiates thousands of unique DNS record requests to the attacker’s domain with each string as

Cisco ASA NetFlow v9 Secure Event Logging (NSEL) is a security logging mechanism that is built on NetFlow Version 9 technology and provides stateful, IP flow tracking for significant events in a flow. NSEL requires a collector to receive and process the exported data records. To configure NSEL, you need to define a flow-export event type under a policy using the Modular Policy Framework (MPF). The event type specifies which events to export, such as flow-create, flow-denied, flow-teardown, flow-update, or all. You also need to configure the NSEL collectors, the template timeout intervals, and the flow-update interval. Optionally, you can disable the redundant syslog messages and reset the runtime counters.

The other statements are false because:

• To view bandwidth usage for NetFlow records, the QoS feature is not required. You can use a NetFlow collector or analyzer to view the bandwidth usage and other statistics from the exported data records.
• A sysopt command cannot be used to enable NSEL on a specific interface. NSEL is enabled globally on all interfaces by default when you configure a flow-export event type under a policy.
• NSEL cannot be used without a collector configured. NSEL exports data records to the configured collectors using NetFlow over UDP. If no collector is configured, the data records are discarded.

References:

• NetFlow Secure Event Logging (NSEL) - Cisco, Topic: Configuring NSEL, page 48-5
• Cisco Secure Firewall ASA NetFlow Implementation Guide, Topic: Configure NSEL Collectors (CLI), Configure Flow-Export Actions Through Modular Policy Framework, Configure Template Timeout Intervals, Change the Time Interval for Sending Flow-Update Events to a Collector, Disable and Reenable NetFlow-related Syslog Messages, Reset Runtime Counters
• Configuring NetFlow on ASA with ASDM - Cisco Community, Topic: Enable NetFlow (ASDM)

3DES is a symmetric-key block cipher that applies the DES algorithm three times to each data block. It was developed to improve the security of DES, which has a small key size and is vulnerable to brute-force attacks. 3DES encrypts traffic by using three different keys, each 56 bits long, to perform three rounds of encryption on the plaintext. The encryption process can be described as follows:

• Encrypt the plaintext with the first key (K1).
• Decrypt the result with the second key (K2).
• Encrypt the result again with the third key (K3).

The final ciphertext is the output of the third encryption. The decryption process is the reverse of the encryption process, using the same keys in reverse order:

• Decrypt the ciphertext with the third key (K3).
• Encrypt the result with the second key (K2).
• Decrypt the result again with the first key (K1).

The final plaintext is the output of the third decryption. 3DES is more secure than DES because it uses a longer effective key length of 168 bits (56 x 3), which makes brute-force attacks more difficult. However, 3DES is also slower than DES because it requires three times more computations. Moreover, 3DES has some weaknesses, such as the meet-in-the-middle attack, which can reduce the effective key length to 112 bits. Therefore, 3DES is not recommended for new applications and has been deprecated by NIST since 201712

References := 1: NIST Special Publication 800-67 Revision 2 Recommendation for the Triple Data Encryption Algorithm (TDEA) Block Cipher 2: What is 3DES encryption and how does DES work? | Comparitech

ExplanationExplanationHow To Troubleshoot ISE Failed Authentications & AuthorizationsCheck the ISE Live LogsLogin to the primary ISE Policy Administration Node (PAN).Go to Operations > RADIUS > Live Logs(Optional) If the event is not present in the RADIUS Live Logs, go to Operations > Reports > Reports >Endpoints and Users > RADIUS AuthenticationsCheck for Any Failed Authentication Attempts in the Log

The Southbound API is used to communicate between Controllers and network devices.

ExplanationThe command crypto isakmp key cisco address 1.2.3.4 authenticates the IP address of the 1.2.3.4 peer by using the key cisco. The address of “0.0.0.0” will authenticate any address with this key

Dynamic ARP Inspection (DAI) is a security feature that validates ARP packets on untrusted interfaces by comparing the MAC address to IP address bindings in the DHCP snooping database or an ARP access-list. If the ARP packet contains invalid or spoofed information, it is dropped and logged. DAI also inspects ARP packets on trusted interfaces, but it does not drop them if they are invalid. Instead, it forwards them to the destination without validation. This allows the switch to support devices that use static IP addresses or have legitimate reasons to send ARP packets with different MAC address to IP address bindings. However, this also means that if a spoofed ARP packet is received on a trusted interface, it will bypass the DAI validation and be forwarded to the destination. This could allow an attacker to poison the ARP cache of other devices and perform a man-in-the-middle attack. Therefore, the correct answer is option B. The switch drops the packet after validation by using the IP & MAC Binding Table. References:

• Understanding and Configuring Dynamic ARP Inspection
• DAI (Dynamic ARP Inspection)
• Dynamic ARP Inspection (DAI) Explanation & Configuration
• Implementing and Operating Cisco Security Core Technologies (SCOR) v1.0

MAB is a fallback mechanism for IEEE 802.1X that allows network access based on the MAC address of the endpoint. However, MAB does not prevent MAC address spoofing, which is a technique used by attackers to impersonate authorized devices and bypass authentication. To mitigate this risk, two catalyst switch security features can be used in conjunction with MAB: 802.1AE MacSec and port security.

802.1AE MacSec is a standard that provides encryption and integrity protection for data frames between two MACsec-capable devices. MacSec also uses a secure key exchange protocol called MKA (MACsec Key Agreement) to establish and maintain cryptographic keys between the peers. By enabling MacSec on the switch ports, the switch can verify the identity and authenticity of the endpoints and prevent unauthorized access or tampering with the data frames.

Port security is a feature that allows the switch to limit the number and type of MAC addresses that can access a port. Port security can be configured to allow only a specific MAC address or a maximum number of MAC addresses per port. Port security can also be configured to take an action when a violation occurs, such as shutting down the port, sending a trap, or dropping packets. By enabling port security on the switch ports, the switch can prevent multiple devices from accessing the same port or deny access to devices with spoofed MAC addresses.

References:

• Implementing and Operating Cisco Security Core Technologies (SCOR) v1.0, Module 2: Network Security, Lesson 2.2: Implementing Network Access Control
• MAC Authentication Bypass Deployment Guide, MAB Benefits and Limitations, MAB Feature Interaction

The Talos IP and Domain Reputation Center is the world’s most comprehensive real-time threat detection network. It collects and analyzes data from millions of web requests, emails, malware samples, open-source data sets, endpoint intelligence, and network intrusions. It assigns a reputation score to IP addresses and domains based on their observed malicious activity and behavior. The reputation score can range from -10 (very malicious) to +10 (very benign). The reputation score can be used to block or allow traffic, or to trigger further inspection or analysis. The Talos IP and Domain Reputation Center allows you to track the reputation of IP addresses for email and web traffic, as well as to look up the category, volume, and history of any IP address or domain. You can also submit feedback or request a change of reputation for any IP address or domain. References 

https://talosintelligence.com/reputation_center/

https://bing.com/search?q=Talos+reputation+center+IP+addresses+email+web+traffic

 Cisco Identity Services Engine (ISE) and AnyConnect Posture module are the best solution to ensure that all endpoints are compliant before users are allowed access on the corporate network. ISE is a policy-based platform that provides secure network access, identity management, and endpoint compliance. AnyConnect Posture module is a component of the AnyConnect Secure Mobility Client that performs posture assessment and remediation on the endpoints. Together, they can enforce policies based on the endpoint’s compliance status, such as the presence and update of the corporate antivirus application and the Windows 10 build version. The administrator can configure posture requirements, profiles, and policies on ISE, and deploy them to the endpoints through AnyConnect. The endpoints will then report their posture status to ISE, which will grant or deny network access accordingly, or redirect them to a remediation portal if needed. References :

Microsegmentation is a network security strategy that breaks a network into smaller network “segments” to boost security and control over data traffic1. Unlike traditional network security, which primarily defends the network’s outer boundaries, microsegmentation focuses on securing individual workloads and devices within the network2. Microsegmentation uses an allow-list model to significantly reduce the attack surface across different workload types and environments3. Microsegmentation is also referred to as application segmentation or east-west segmentation in a multicloud data center4.

Option B is the correct description of microsegmentation, as it captures the essence of applying a zero-trust model and specifying how applications on different servers or containers can communicate. Option A is incorrect, as deploying a container orchestration platform is not a sufficient condition for microsegmentation. Option C is incorrect, as deploying host-based firewall rules is not a necessary condition for microsegmentation. Option D is incorrect, as implementing private VLAN segmentation is a different technique from microsegmentation. References: An Introduction to Microsegmentation in Network Security. What Is Micro-Segmentation? - Cisco. What Is Microsegmentation? - Palo Alto Networks. What Is Microsegmentation in Networking? Beginner’s Guide.

 A security application that notifies a controller within a software-defined network architecture about a specific security threat is using a northbound API. A northbound API is an interface that enables communication between the SDN controller and the applications or management systems that use the network services1. A security application can use a northbound API to send alerts, requests, or commands to the SDN controller, which can then take appropriate actions on the network devices or policies2. For example, a security application can use a northbound API to inform the SDN controller about a malicious traffic pattern, and the SDN controller can then block or redirect the traffic using a southbound API3.

References: 1: What is Software-Defined Networking (SDN)? | VMware Glossary 2: Intent-Based Networking’s Next Evolution: The DNA Center Platform - Cisco Blogs 3: Cisco SDN Security: Securing the Software Defined Network - Cisco

PFS stands for Perfect Forward Secrecy, which is a property of some cryptographic protocols that ensures that the compromise of a long-term key does not affect the security of past or future sessions. PFS provides the highest level of protection against brute-force attacks, because even if an attacker manages to break the long-term key, they cannot decrypt the previous or subsequent communications that use different session keys. PFS is achieved by using ephemeral or temporary keys that are derived from a Diffie-Hellman key exchange, and are not based on the long-term key. Therefore, each session has a unique and independent key that is not stored or reused. PFS is supported by some protocols such as TLS, SSH, and IPsec123. References := 1: Implementing and Operating Cisco Security Core Technologies (SCOR) v1.0, Module 4: Securing Networks with Cisco Firepower Next Generation IPS, Lesson 4.1: Deploying Cisco Firepower Next-Generation IPS, Topic 4.1.2: Cisco Firepower NGIPS Device Management 2: What is Perfect Forward Secrecy? | Baeldung on Computer Science4 3: Perfect Forward Secrecy - an overview | ScienceDirect Topics5