H12-711_V4.0 Exam Dumps : HCIA-Security V4.0 Exam

Explanation From HCIA-Security documents:

IKE-based SA establishment is designed to automate IPsec parameter negotiation and key management, which makes it especially suitable for environments where configuring many tunnels manually would be inefficient. That is why B is correct: IKE scales better for medium and large networks because it negotiates policies, authenticates peers, and builds SAs dynamically instead of relying on fixed, manually configured keys.

A is incorrect because Security Associations have lifetimes. Both IKE SAs and IPsec SAs are created with time-based and/or traffic-based lifetimes and must be refreshed or renegotiated when they expire to maintain security. Permanent SAs would increase risk because long-lived keys are more exposed to compromise.

C is correct : SPI is a 32-bit identifier used by the receiver to find the correct SA for inbound traffic, and it is typically chosen by the receiving side in a way that avoids collisions—commonly treated as randomly generated in foundational descriptions.

D is correct because IKE uses Diffie-Hellman to derive shared keying material securely over an untrusted network, and then refreshes keys by rekeying based on SA lifetime, achieving dynamic updates.

Huawei firewalls support creating multiple sub-interfaces on a single physical interface such as GE0/0/1 so that one physical link can carry traffic for multiple VLANs. Each sub-interface is configured with an 802.1Q VLAN tag, which allows it to logically represent one VLAN or one Layer 3 gateway interface for that VLAN. This design is commonly used when the firewall connects to a switch through a trunk and needs to provide routing and security control for several VLANs simultaneously.

The statement is incorrect because sub-interfaces can be added to security zones. A security zone is a logical security domain used for policy enforcement, and Huawei firewalls allow both physical interfaces and logical interfaces (including VLAN sub-interfaces) to be assigned to zones. This is essential for implementing interzone security policies between VLANs. For example, if two VLANs are mapped to two different sub-interfaces, placing each sub-interface into a different zone allows the firewall to apply access control, inspection profiles, and NAT based on zone-to-zone rules. Therefore, the claim that sub-interfaces cannot be added to security zones is false.

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 .