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

Application-layer protocols provide network services directly to user applications and define how clients and servers exchange application data. DNS is an application-layer protocol used to translate domain names into IP addresses (and perform related record lookups), enabling applications to locate services by name instead of by numeric address. Telnet is also an application-layer protocol that provides remote terminal access; it allows a user to interact with a remote system’s command-line interface over the network (though it is insecure because it transmits data in plaintext). HTTP is an application-layer protocol used for web communication, defining request/response behavior between browsers (clients) and web servers for transferring web pages and related content.

In contrast, ARP is not an application-layer protocol. ARP operates at the boundary of Layer 2/Layer 3 to map an IPv4 address to a MAC address on the local network segment, supporting frame delivery on Ethernet. Therefore, the application-layer protocols here are DNS, Telnet, and HTTP.

On Huawei firewalls, traffic direction is determined according to the priority of security zones . When traffic moves from a low-priority zone to a high-priority zone , that direction is called Inbound . For example, traffic going from the Untrust zone to the Trust zone is considered inbound because Untrust has a lower security priority than Trust.

By contrast, traffic moving from a high-priority zone to a low-priority zone is called Outbound . A common example is internal users in the Trust zone accessing resources on the Internet in the Untrust zone. This zone-priority concept is important because firewall security policies, packet filtering behavior, and session control are all evaluated according to the source zone and destination zone.

Understanding inbound and outbound directions is essential when configuring interzone security policies. Administrators must know whether traffic is flowing from low to high priority or high to low priority in order to apply the correct permit, deny, NAT, and inspection rules. Since the question specifically asks for the direction from a low-priority zone to a high-priority zone, the correct answer is Inbound .

Explanation From HCIA-Security documents:

L2TP is a Layer 2 tunneling protocol designed to carry PPP frames across an IP network by encapsulating them inside L2TP tunnels. That’s why statement B is correct: L2TP’s job is to transport PPP traffic through a tunnel between an L2TP Access Concentrator and an L2TP Network Server. In typical remote-access VPN use, employees connect from outside (hotel, home, mobile network) and reach internal resources through the VPN, so A and D match common deployment scenarios.

The incorrect statement is C because PPP is not routable over the public Internet by itself. PPP was originally meant for point-to-point links (like dial-up or serial links). On an IP network such as the Internet, PPP frames must be encapsulated by a method like L2TP (often paired with IPsec for confidentiality and integrity) or converted via technologies such as PPPoE/PPPoA for specific access networks.

Explanation From HCIA-Security documents:

All four statements describe standard PKI roles and structure. A PKI entity is any certificate holder or relying participant that uses PKI services, which includes people, organizations, network devices, servers, and even application processes, so A is correct. PKI trust is commonly built using a CA hierarchy, where the root CA anchors trust and subordinate CAs issue certificates under the root’s authority, so B is correct. The CA is the core trusted component that signs (issues) certificates and manages their lifecycle activities such as renewal, suspension or revocation publication, and certificate status services, so C is correct. In many enterprise implementations, the PKI system is presented as three major roles: entities that request/use certificates, the RA that performs identity verification and approval of requests, and the CA that issues certificates based on validated requests, so D is also correct.

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:

In a PKI, certificate revocation is mainly about requester authentication and approval, not about using one mandatory communication method. The RA is responsible for verifying the applicant’s identity and the legitimacy of the revocation request, then submitting the validated request to the CA. After approval, the CA updates the certificate status, typically by publishing an updated CRL or providing status through OCSP, so relying parties can detect that the certificate is no longer trustworthy.

A “signed and encrypted email” is only one possible way to send a revocation request, but it is not required. In practice, organizations may accept revocation requests through a portal, ticketing system, dedicated PKI management interface, phone with pre-agreed authentication, or other controlled channels. If email is used, digital signature can help prove the requester’s identity and protect integrity, while encryption is optional and depends on policy because the key need is authorization, not confidentiality.

Explanation From HCIA-Security documents:

AAA provides a unified framework for Authentication, Authorization, and Accounting, and on Huawei devices the AAA authentication method can be selected according to the management and deployment requirements. Local authentication uses user accounts stored on the device itself, which is suitable for small environments, emergency access, or when external servers are unavailable. RADIUS authentication relies on a centralized RADIUS server, commonly used for large-scale user access control and unified credential management. HWTACACS authentication is another centralized mode that supports fine-grained control and is often preferred in scenarios requiring stronger separation of authentication and authorization, as well as detailed command-level management in some deployments. In addition, AAA can be configured for no authentication (also called none), meaning the device does not verify user identity for a specific access scenario. This mode is typically used only in controlled environments or for specific services where authentication is handled elsewhere, because it reduces security. Therefore, all listed modes are supported by AAA.

This statement is TRUE . When an administrator logs in to a device through the web UI over HTTPS , the device acts as the HTTPS server and presents a local certificate to the web browser during the TLS handshake. If this certificate is issued by a CA trusted by the browser , the browser can verify the certificate chain, confirm the identity of the device, and establish an encrypted session without certificate warning messages.

This process improves security in two important ways. First, it provides server identity authentication , which helps the administrator confirm that the browser is connected to the legitimate device rather than an impersonated or spoofed host. Second, once the certificate is trusted and the TLS session is established, the communication is encrypted and protected for integrity , which reduces the risk of eavesdropping, tampering, and man-in-the-middle attacks during administrator login.

If a trusted CA certificate is not used, administrators may see browser warnings and may not be able to reliably confirm the server identity. Therefore, configuring a CA-issued certificate for HTTPS management helps prevent malicious attacks and ensures more secure administrator access.

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 .

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 .

The correct operation is D because email attachments are a common carrier for malware, phishing payloads, ransomware, Trojans, and malicious scripts. In enterprise security practice, a user should not trust an attachment only because the message looks work-related or appears to come from a company mailbox . Attackers can spoof sender information, disguise malicious content, or compromise legitimate accounts. Therefore, simply checking the content or sender is not enough to ensure safety.

A safer process is to verify the sender and the email details carefully , such as the address, subject, wording, unexpected urgency, and whether the attachment type matches the business context. After that, the attachment should be scanned with antivirus or endpoint security software before opening or saving it. This helps detect known malicious files and reduces the chance of infecting the host or internal network.

Option A is unsafe because work relevance alone does not prove the file is harmless. B is clearly wrong because attachments can directly affect information security. C is also unsafe because internal-looking mail can still be malicious. Therefore, D is the correct answer.

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 IKEv1 Phase 1 aggressive mode, the negotiation completes in three messages, unlike main mode which uses six.

Message 1 (Initiator → Responder): Contains the IKE proposal, Diffie-Hellman public value, nonce, and the initiator’s identity information.

Message 2 (Responder → Initiator): Returns the selected proposal, responder’s Diffie-Hellman public value, nonce, identity information, and authentication data. At this stage, the initiator can authenticate the responder.

Message 3 (Initiator → Responder): Carries the initiator’s authentication data, allowing the responder to verify and authenticate the initiator.

Therefore, the primary function of message 3 is to provide authentication information so that the responder can confirm the identity of the initiator.

Options A and B correspond to earlier negotiation steps, and C describes part of message 2. Hence, the correct answer is D.

Explanation From HCIA-Security documents:

3-tuple NAT is used to publish internal services to external users by translating destination IP address, destination port, and protocol so that an Internet user can reach an intranet server using a public address and specific service port. So the first part of the statement about enabling proactive external access through translated addresses and ports matches what 3-tuple NAT is used for.

However, NAT translation and firewall access control are two different functions. NAT only defines how addresses and ports are translated; it does not replace the firewall’s security policy decision. On a Huawei firewall, whether a packet is allowed to pass is determined by the configured security policy (interzone policy). If no relevant security policy exists to permit the traffic from the external zone to the internal zone and the mapped service, the firewall will not automatically allow it just because a NAT mapping is present.

Therefore, without an appropriate permit security policy, the access packets will be denied even if 3-tuple NAT is configured.

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 .