H12-811_V1.0 Exam Dumps - Huawei HCIA-Datacom Questions and Answers

Comprehensive Explanation: The country code setting on wireless devices like access points determines the allowable transmission frequencies and maximum transmission power based on the regulatory requirements of the specific region. For example, certain frequency channels or power levels may be restricted in different countries to avoid interference with other services, and the country code configuration ensures that the device operates within those legal limits.

Comprehensive Explanation: A routing table contains information necessary for the router to determine the best path to forward packets. This includes the destination network or subnet (Destination/Mask), the next-hop address (the IP address of the next device in the path), and the cost (metric) associated with the route. MAC addresses are used at the Data Link layer (Layer 2) for local network communication and are not part of the routing table, which operates at the Network layer (Layer 3).

CAPWAP (Control and Provisioning of Wireless Access Points) is a protocol that enables centralized control of Fit APs by an AC (Access Controller).

Option A (Incorrect): CAPWAP tunnels only control traffic, while data traffic can be sent via direct forwarding or tunneled forwarding.

Option B (Incorrect): A Fit AP can discover an AC via multiple methods, including broadcast, static configuration, or DHCP Option 43.

Option C (Correct): APs encapsulate user data into CAPWAP packets and send them to the AC for further processing.

Option D (Incorrect): CAPWAP is based on UDP, not TCP, for better efficiency and lower latency.

Thus, the correct answer is C.

Detailed Explanation:

• Option A: Incorrect. UDP (User Datagram Protocol) does not use SYN or ACK flags, as it is a connectionless protocol and does not establish a connection before data transfer. SYN and ACK flags are features of TCP (Transmission Control Protocol), which establishes connections using a three-way handshake. (Reference: HCIA-Datacom Training Material, Transport Layer Protocols)

• Option B: Incorrect. UDP is suitable for delay-sensitive traffic (such as video or voice) because of its low overhead. However, UDP does not have a sequence number field or support reassembly, as it does not guarantee packet order or reliability. (Reference: HCIA-Datacom Training Material, UDP Characteristics)

• Option C: Correct. TCP requires a three-way handshake to establish a connection and a four-way handshake to terminate it, involving SYN, ACK, FIN flags for reliability. (Reference: HCIA-Datacom Training Material, TCP Connection Establishment and Termination)

• Option D: Correct. The well-known port number range is defined as 0 to 1023, and these are reserved for widely used protocols such as HTTP, FTP, and DNS. (Reference: HCIA-Datacom Training Material, Port Numbering)

Detailed Explanation:The command forward-mode direct-forward is used to configure the AC to enable direct forwarding, meaning that the AP will forward user data packets directly to the network without tunneling them through the AC, improving efficiency by reducing the load on the AC​.

In VRP, the "-a" parameter in the ping command allows specifying a source IP address for the echo request. This can be helpful in testing connectivity from a specific interface on the device, which is useful in verifying path accessibility or troubleshooting issues with certain network segments​.

Wireless networks commonly use Access Controllers (ACs) and Access Points (APs) to manage user connectivity.

Option A (Incorrect): Fat APs operate independently and do not require an AC to function. Instead, Fit APs require ACs to manage them centrally.

Option B (Correct): An AC (Access Controller) is usually deployed at the aggregation layer of a network. It provides centralized control over Fit APs, ensuring high-speed, secure, and reliable WLAN services. This is the standard design in enterprise WLAN architectures.

Option C (Incorrect): Fit APs do not handle authentication and forwarding on their own. Instead, they rely on an AC for these functions.

Option D (Incorrect): Many wireless devices (including APs and ACs) have wired interfaces for uplink connectivity to switches or other network devices.

Thus, the correct answer is B. An AC is usually deployed at the aggregation layer of a network to provide high-speed, secure, and reliable WLAN services.

Advanced ACLs (3000-3999) allow filtering based on:

Source and Destination IPs

Protocol Number (C - Correct)

Destination Port Number (B - Correct)

Time-range (D - Correct)

A (Incorrect): ACLs do not filter based on the source interface, but rather on IPs, ports, and protocols.

Thus, the correct answer is A (Source Interface).