Pass the Huawei HCIA-Security H12-711_V4.0 Questions and answers with Dumpstech

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.

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.