HCIA-Security H12-711_V4.0 Book

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.

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 .