Free Huawei H12-711_V4.0 Practice Exam with Questions & Answers | Set: 3

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:

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.

By default, a firewall’s security policy is mainly used to control unicast traffic between security zones. Unicast packets are the normal one-to-one communication packets exchanged between a single source host and a single destination host. Because most user service traffic, such as web access, file transfer, remote login, and application communication, is carried in unicast form, firewall security policies are primarily designed to inspect and control this type of traffic.

Broadcast packets are typically used for local network discovery or service announcements within the same broadcast domain, and they are not the standard focus of interzone security policy control. Multicast traffic is one-to-many communication and usually requires additional multicast-specific handling or routing mechanisms rather than ordinary default security policy treatment. Anycast is a special addressing and routing method rather than the usual packet-control category emphasized in firewall default policy behavior.

In Huawei firewall policy design, when administrators configure permit or deny rules between zones, those rules are generally intended to manage unicast service traffic . Therefore, among the options listed, the packet type controlled by a firewall’s security policy by default is Unicast .

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 .

Explanation From HCIA-Security documents:

PKI is mainly used where digital certificates are needed to prove identity, distribute public keys safely, and support functions such as authentication, encryption, and digital signatures . HTTPS web login relies on server certificates (and sometimes client certificates) to build trust and establish encrypted sessions, so D is a classic PKI scenario. SSL VPN also typically uses certificates for gateway identity and often for user/device authentication, so A fits PKI usage as well. IPv6 SEND Secure Neighbor Discovery uses cryptographic mechanisms (such as CGA and signature-based protection) that depend on certificates, making C another PKI-related scenario.

By contrast, IPsec VPN does not necessarily depend on PKI in all deployments. IPsec can authenticate peers using pre-shared keys or other methods without certificates, so it is commonly treated as not strictly a PKI application scenario in basic classification questions. In many training outlines, PKI scenarios are highlighted as HTTPS, SSL VPN, and IPv6 SEND, while IPsec is presented as a separate VPN technology that may or may not integrate certificates. Therefore, the best answer is B .

A Denial of Service attack is intended to make a host, server, or network service unavailable to legitimate users. It usually works by exhausting system resources such as bandwidth, CPU, memory, connection tables, or buffers, so valid users cannot access the service normally. Therefore, statement B is correct because the essential purpose of a DoS attack is to interrupt services or block resource access on the target.

Statement C is also correct. Many DoS attacks attempt to consume queue space, session resources, or buffers on the target so that new connection requests cannot be processed. This is a common way of making a service unavailable. Statement A can also be correct in the context of some DoS methods, because attackers may use IP spoofing to hide their identity, bypass simple filtering, or increase the difficulty of tracing the attack source.

Statement D is incorrect because DoS attacks are designed to affect availability , not to create unrecoverable physical damage to hardware. They may crash systems, overload services, or interrupt access, but they do not normally destroy the target device physically.

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 .