Comprehensive and Detailed Explanation From Exact Extract:

To meet the requirement of restricting inbound traffic and allowing outbound traffic, two components are most appropriate:

D. Firewall – A firewall enforces ingress and egress traffic policies. It can be configured to deny all inbound traffic by default and allow all outbound traffic, meeting the security policy requirement.

E. Network Security Group (NSG) – In cloud environments such as Azure, NSGs serve as virtual firewalls at the subnet or interface level. NSGs allow you to define rules that block or allow inbound and outbound traffic, and they are the preferred method for enforcing network access rules for cloud resources.

Relevant Extract from CompTIA CloudNetX CNX-001 Study Guide — under “Cloud Network Security Configuration”:

“Network security groups and firewalls are key to enforcing inbound and outbound traffic restrictions in hybrid and public cloud environments.”

“NSGs are used to define network access control policies for cloud resources at the subnet or NIC level.”

Other options:

A. Application gateway controls HTTP/S traffic at Layer 7 but does not manage full access policy.

B. IPS detects/prevents malicious behavior but is not primarily used for general traffic restriction.

C. Port security restricts MAC addresses on switch ports, applicable in LANs, not cloud.

F. A screened subnet (DMZ) can provide additional isolation but is not required for basic traffic control.

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Comprehensive and Detailed Explanation From Exact Extract:

A. An explicit allow rule in the Network Security Group (NSG) permitting Server A (10.2.3.9) to communicate with Server B (10.2.2.7) ensures intra-cloud communication between segments.

C. A deny rule that blocks any inbound access from external sources (0.0.0.0/0 ? internal range 10.2.0.0/16) effectively prevents unsolicited inbound traffic from the public internet, securing the internal servers.

Relevant Extract from CompTIA CloudNetX CNX-001 Study Guide — under “Cloud Security Groups and Firewall Policies”:

“NSGs should be configured with least privilege principles. Allow intra-subnet or intra-application communication while explicitly denying unsolicited internet traffic.”

“Ingress and egress filtering policies should block all traffic by default and permit only what’s required.”

Other options:

B. Incorrect – this allows internal range to internet, which is not requested.

D & E. Apply to outbound policies, not relevant to the need to block inbound external access.

F. Incorrect – this denies internal resources from going outbound, not inbound protection.

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Comprehensive and Detailed Explanation From Exact Extract:

PF_RING is a high-performance packet capture and filtering framework that allows IDS systems to handle large volumes of traffic efficiently. By offloading and filtering out traffic that is known and trusted (such as HTTPS traffic from a patch server), the IDS can focus on analyzing critical traffic and reduce dropped packets.

Relevant Extract from CompTIA CloudNetX CNX-001 Study Guide — under “Traffic Filtering and IDS Performance Optimization”:

“Advanced filtering solutions like PF_RING allow offloading of known trusted traffic, reducing processing overhead on IDS systems and improving visibility into meaningful events.”

Other options:

A. Directly configuring the IDS to ignore traffic may bypass too much, affecting visibility.

C. BPF filters on the tap itself may interfere with other systems using the tap.

D. Disabling the IDS temporarily removes all visibility — a poor security practice.

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