H12-711_V4.0 HCIA-Security V4.0 Exam Questions and Answers

Use SSL VPN to access the firewall to trigger authentication → Access user

Use HTTP to access the intranet web server to trigger authentication → Internet access user

Log in to the firewall through Telnet, SSH, or web to trigger authentication → Administrator

These authentication modes correspond to different user roles on a Huawei firewall. An Access user is typically a user who connects to enterprise resources through technologies such as SSL VPN . In this case, the user accesses the firewall as a secure access gateway, and authentication is triggered when the SSL VPN session is initiated.

An Internet access user usually refers to a common end user whose identity must be verified before being allowed to access network resources through the firewall. A common way to trigger this authentication is by using HTTP to access an intranet or web resource , which leads to Portal-based identity verification and access control.

An Administrator is different from ordinary service users because this role is responsible for managing and configuring the firewall itself. Therefore, authentication for an administrator is triggered when the person logs in directly to the firewall through Telnet, SSH, or the web management interface .

So the correct matches are: SSL VPN → Access user , HTTP intranet access → Internet access user , and Telnet/SSH/web login → Administrator .

Explanation From HCIA-Security documents:

HTTPS protects web-based management by combining encryption with server identity authentication . For the browser to trust the device’s HTTPS service, the device must present a server certificate that can be validated by the browser. That is why administrators often configure the device to use a local certificate (the device’s certificate) that is issued by a trusted CA or whose CA chain has been imported into the browser/OS trust store. When the certificate is trusted, the browser can verify the certificate chain, validity period, and hostname binding, which helps prevent attackers from impersonating the device during login.

If a device uses a self-signed or untrusted certificate, the browser shows warnings and users may click through them, increasing the risk of man-in-the-middle attacks and credential theft. Using a CA-trusted certificate strengthens administrator logins by ensuring the management page you connect to is genuinely the intended device and that the session is encrypted end-to-end.

Protocol identification and analysis

Application data reassembly

Signature matching

Attack response

The correct IPS processing order starts with protocol identification and analysis . Before an IPS can judge whether traffic is malicious, it must first determine what protocol is being used and analyze the packet structure according to the expected protocol behavior. This helps the device understand whether the traffic is HTTP, FTP, SMTP, DNS, or another protocol and prepares it for deeper inspection.

After that, the IPS performs application data reassembly . Many attacks are not visible in a single packet, so the IPS must reconstruct fragmented or segmented traffic into complete application data. This allows the device to inspect the real payload content rather than isolated packet pieces.

Once the data is reassembled, the IPS performs signature matching . At this stage, the traffic content and behavior are compared with known attack signatures, protocol anomalies, and detection rules to determine whether the traffic matches a malicious pattern such as injection, buffer overflow, or directory traversal.

Finally, the IPS performs the attack response . Based on the detection result, it may permit, block, reset, alarm, or log the traffic. Therefore, the correct order is D → A → B → C .

In IPsec ESP transport mode , the authentication process protects most of the ESP packet except the outer IP header and the authentication data field itself. Specifically, the authentication calculation covers the ESP header, the encrypted payload (such as the TCP header and application data), and the ESP trailer . The IP header is not included , because it may change during packet transmission, and the ESP authentication data field is also excluded because it stores the result of the authentication calculation.

Looking at the packet structure in the figure, the order is: IP Header → ESP Header → TCP Header → Data → ESP Tail → ESP Auth Data . The correct authentication range therefore begins at the ESP header and ends at the ESP tail , but it does not include the IP header or the ESP authentication data.

In the diagram, option 3 represents the range starting from the ESP header and ending at the ESP tail , which matches the actual authentication coverage of ESP in transport mode. Therefore, the correct answer is 3 .

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.

Explanation From HCIA-Security documents:

IPS works by identifying malicious traffic patterns and behaviors in network data. An IPS signature is a set of detection rules that describe known attack characteristics, such as specific byte sequences in payloads, abnormal protocol fields, exploit patterns, or behavior indicators that match a recognized threat. When traffic passes through the firewall with IPS enabled, the device performs protocol decoding and (when needed) stream or application data reassembly so it can inspect complete content instead of isolated packets. After that, it compares the reconstructed traffic against the IPS signature database. If a match is found, the firewall determines the traffic is malicious and then takes the configured action, such as blocking packets, resetting the connection, discarding the session, and generating logs/alarms for visibility and auditing. This signature-based comparison is a core detection method of IPS and is why keeping the signature library updated is important: new attack techniques require new or improved signatures. Therefore, the statement is correct: the firewall detects and defends by comparing data flows with IPS signatures.

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.

Explanation From HCIA-Security documents:

The statement is incorrect for two reasons. First, in asymmetric cryptography, encryption and decryption are not restricted to only “public encrypt, private decrypt.” That is one common confidentiality use case (for example, encrypting a session key so only the holder of the matching private key can recover it). However, asymmetric key pairs are also used the other way around for digital signatures : the sender uses the private key to generate a signature (often described conceptually as “private-key operation”), and others use the public key to verify it. So it’s not true that “only public keys can be used to encrypt data” in all cases or contexts.

Second, calling the process “irreversible” is misleading. Asymmetric encryption is designed to be reversible for authorized parties : ciphertext can be decrypted with the corresponding key (private key for public-key encryption). What is “one-way” is the practical difficulty of recovering the plaintext without the correct key. Therefore, the correct choice is FALSE .

A packet filtering firewall mainly works by examining the header information of packets and making forwarding or blocking decisions based on predefined rules. Its inspection is primarily focused on the network layer , where it checks information such as the source IP address , destination IP address , protocol type, and related packet header fields. Because of this, the correct answer is Network layer .

Packet filtering firewalls can also use some transport-layer information such as TCP or UDP port numbers in practical policy matching, but their fundamental classification in traditional firewall technology is based on network-layer packet filtering rather than deep inspection of application content. They do not analyze user data in the same detailed way as application-layer gateways or next-generation firewalls.

The physical layer only deals with bit transmission and hardware signaling, so it is not the layer used for packet filtering decisions. The data link layer focuses on MAC addresses and frame transmission within a local segment, while the application layer deals with application protocols such as HTTP, FTP, and DNS. Therefore, for a packet filtering firewall, the correct layer checked is the Network layer .

This statement is TRUE . A DMZ is a special security zone used to place servers that must provide services to external users while still being isolated from the internal trusted network. Typical examples include WWW servers, FTP servers, mail servers, and DNS servers . These systems need to be accessible from outside networks such as the Internet, but placing them directly inside the internal network would increase security risk.

The purpose of the DMZ is to create a buffer area between the Untrust zone and the Trust zone. External users can be allowed to access the public-facing servers in the DMZ according to security policies, while access from the DMZ to the internal network can be more strictly restricted. This design helps reduce the chance that an attacker who compromises a public server can directly reach sensitive internal systems.

On Huawei firewalls, the DMZ is one of the default security zones and is specifically intended for such semi-public service devices. Therefore, devices that provide external network services, such as WWW and FTP servers, can correctly be deployed in the DMZ .

Intrusion Prevention (IPS) detects and blocks attacks primarily by analyzing traffic patterns and payload characteristics against known signatures, protocol anomalies, and behavioral rules. Many common application-layer exploits have recognizable request structures that IPS engines can match.

An injection attack (such as SQL injection or command injection) typically contains suspicious characters, keywords, and abnormal parameter patterns within application requests. IPS signatures can detect these malicious payload characteristics and either block the session or generate alarms. Directory traversal attacks also have distinct patterns, such as attempts to access unauthorized paths using sequences like ../ (or encoded variants). These are classic web-attack signatures commonly covered by IPS rule sets. Buffer overflow attacks often exploit protocol or application parsing weaknesses by sending overly long fields, malformed headers, or abnormal protocol sequences; IPS can detect these through signature matching and protocol anomaly detection.

A Trojan horse , however, is malware residing on an endpoint (often delivered via files, email attachments, downloads, or user execution). While some network security features (like antivirus/URL filtering/sandboxing) may detect Trojan delivery or command-and-control traffic, “Trojan horse” itself is not typically classified as an IPS-detected attack type in this context. Therefore, A, B, and D are correct.

This statement is TRUE . On Huawei firewalls, security policies are mainly used to control traffic between different security zones . The firewall determines policy matching based on the source zone and destination zone , and these interzone policies decide whether traffic is permitted or denied.

For traffic between users in the same zone , permit security policies generally do not need to be configured. This is because hosts and interfaces belonging to the same security zone are considered to have the same trust level, and their communication is not normally controlled by interzone security policy rules in the same way as traffic moving from one zone to another. In other words, the main purpose of zoning is to define boundaries between different trust levels, not to force permit rules for communications inside a single zone.

This behavior simplifies firewall policy deployment. Administrators mainly need to focus on policy design for traffic such as Trust to Untrust , Untrust to DMZ , or DMZ to Trust , where different trust levels exist. Therefore, for traffic between users in the same zone , a permit action security policy is generally not required .

Explanation From HCIA-Security documents:

TCP is a connection-oriented transport protocol, so it must establish a reliable session before user data can be exchanged. To create the session, TCP uses the three-way handshake: the initiator sends a SYN to request a connection and advertise its initial sequence number, the responder replies with SYN/ACK to acknowledge the request and provide its own initial sequence number, and finally the initiator sends an ACK to confirm receipt. This process confirms bidirectional reachability, synchronizes sequence numbers, and prepares both ends for reliable delivery, retransmission control, and flow control.

To end a TCP connection gracefully, TCP performs an orderly close in both directions (full-duplex). One endpoint sends FIN to indicate it has no more data to send, the peer responds with ACK . When the peer is also ready to stop sending, it transmits its own FIN , and the original endpoint responds with a final ACK . Because each direction is closed independently, termination is typically described as a four-way handshake .

Explanation From HCIA-Security documents:

In a typical PKI workflow, the CA is mainly responsible for certificate issuance and lifecycle management, but it usually does not handle direct identity verification for most end users. Instead, the user submits a certificate application request (often a CSR) through a defined enrollment channel, and the RA performs the key step of validating the requester’s identity and authorization according to the organization’s certificate policy. After the RA approves the request, it is forwarded to the CA for signing and issuance. This separation of duties improves security and scalability: the CA stays protected and focused on signing operations, while the RA enforces registration, approval, and identity-proofing processes close to the user or business unit.

Therefore, saying “in most cases the user applies to the CA and the CA approves the application” is inaccurate in standard enterprise PKI designs. The CA issues the certificate, but approval and verification are commonly handled by the RA, with the CA acting on the RA’s validated decision.

Explanation From HCIA-Security documents:

A packet filtering firewall mainly makes decisions based on L3/L4 header information such as source/destination IP address, protocol, and port, usually through static ACL rules . Because it does not deeply understand application behavior and typically does not track full session state like a stateful inspection firewall, it has several limitations.

A is a disadvantage because basic packet filtering is often implemented as rule-by-rule matching; under heavy traffic or intentionally flooded traffic, performance can degrade and the device may be pressured by DoS-style loads, especially if rules are long or the platform is resource-limited.

B is also a disadvantage: packet filtering that trusts only IP information can be bypassed by IP spoofing in certain scenarios, allowing traffic to appear as if it comes from an allowed address.

C is correct because packet filtering relies on static policies , which struggle to handle dynamic connections, complex services, and fine-grained user-based control.

D is not a disadvantage of packet filtering; dynamic connection status lists are a feature of stateful firewalls, not simple packet filters.