Huawei Updated H12-821_V1.0 Exam Questions and Answers by klay

The hardware modules of Huawei modular devices and their functions are:

Main Processing Unit (MPU): Provides control and management planes for the entire system, responsible for protocol processing, system security, and software upgrades.

Switch Fabric Unit (SFU): Provides the data plane, enabling high-speed data switching between service modules.

Line Processing Unit (LPU): Manages data forwarding, offering various interfaces (optical and electrical) for data access​​.

In a stateful inspection firewall, if the status detection mechanism is enabled, it tracks and validates the state of connections using the session table. If there is no session table and a SYN+ACK packet reaches the firewall, it checks the security policy. If the policy explicitly permits the packet, it will pass through the firewall, but no session table will be created without the initial SYN packet. The other options are either incorrect or misrepresent the behavior of stateful inspection ​.

The operator between if-match clauses under a node is AND, meaning all conditions must be satisfied. However, the operator between nodes is OR, meaning a route matching any node will pass the route-policy ​.

When the level of an IS-IS interface is changed, the adjacency must be re-established because IS-IS adjacencies are formed based on matching levels (Level-1, Level-2, or both). Other changes, such as cost or hello intervals, do not disrupt the existing adjacency but might impact routing metrics or timing ​.