Free Practice Questions for Huawei H12-711_V4.0 Exam

A firewall is primarily a boundary security device used to control traffic between networks of different trust levels, such as an intranet and an extranet or the Internet. Its key capability is enforcing access control based on security policies, which helps prevent unauthorized traffic and information flows from less trusted networks into more trusted ones. That is why statement B is correct: by applying security policies, the firewall can block unauthorized access attempts and prevent unapproved data from the extranet reaching intranet resources.

The other statements are incorrect because they overstate firewall capabilities. A firewall alone cannot guarantee protection against zero-day vulnerabilities, because zero-days may not match known signatures or rule patterns, and prevention often requires multiple layers such as endpoint hardening, behavioral detection, and timely patching. It also cannot defend against all external threats, since attacks can bypass controls through encrypted traffic, insider misuse, misconfigurations, or compromised endpoints. Even if a firewall supports antivirus features, it does not replace endpoint and network antivirus deployment; layered security is still required.

A. Scanning attacks → Attackers use ICMP packets to probe the target IP address to identify active hosts that connect to the target network.

B. Malformed packet attacks → Attackers send considerable malformed packets in an attempt to crash targeted hosts or servers.

C. Special packet control attacks → Such attacks are reconnaissance activities for attacks but not real attacks. That is, attackers send special packets to probe network structures.

In HCIA-Security, single-packet attacks are commonly categorized by the purpose and structure of the packets being sent. Scanning attacks are mainly used to discover targets and collect information before a real attack begins. A common example is using ICMP probe packets to identify whether hosts are alive and reachable on a network. This makes the ICMP host-discovery description the correct match for scanning attacks.

Malformed packet attacks involve sending packets with abnormal, invalid, or deliberately corrupted structures. Their purpose is to exploit weaknesses in protocol handling or operating system processing so that the target host, device, or server becomes unstable, crashes, or stops responding. Therefore, the description about sending many malformed packets to crash targets clearly matches this category.

Special packet control attacks are also more related to probing than direct destruction. In this case, attackers send specially crafted control or probe packets to learn network structure, device behavior, or service characteristics. These activities are considered reconnaissance rather than full attacks. That is why the description about probing network structures with special packets belongs to special packet control attacks.

This statement is correct because it accurately reflects the basic objective of information security. In HCIA-Security, information security is concerned with protecting information assets and the systems that store, process, and transmit them. These assets include hardware devices, software platforms, network resources, and the data itself. The purpose is to prevent unauthorized access, accidental loss, malicious tampering, disclosure, destruction, or interruption of services.

Information security is not limited to confidentiality alone. It also includes maintaining integrity , which means preventing unauthorized modification of data, and availability , which means ensuring that systems and services remain usable and continuous for authorized users. In practical terms, this means using controls such as access management, firewalls, intrusion prevention, antivirus protection, encryption, backup, authentication, and monitoring to reduce both accidental and intentional threats.

The phrase about ensuring proper system running and uninterrupted information services also matches the availability goal of security. Therefore, the statement correctly describes the overall aim of information security and is TRUE .

The incorrect statements are A and C .

A router works at the network layer and is used to connect different networks. By default, a router separates broadcast domains , because broadcasts are not forwarded from one interface to another. At the same time, each router interface also represents an independent network segment, so routers effectively separate collision domains as well. Therefore, the statement that routers can isolate broadcast domains but not collision domains is incorrect.

A Layer 2 switch works at the data link layer. Each switch port forms a separate collision domain , which is why switches can isolate collision domains. However, by default, all ports in the same VLAN still belong to the same broadcast domain , so switches forward broadcast traffic out all relevant ports. That makes statement B correct and statement D correct.

Statement C is incorrect because routers generally do not forward broadcast packets . Preventing broadcast propagation between networks is one of the key differences between routers and switches. Therefore, the incorrect options are A and C .