H12-811_V1.0 Huawei HCIA-Datacom V1.0 Exam Free Practice Exam Questions (2026 Updated)

Analysis of Possible Causes:

Option A: " The administrator account has been disabled " is a possible cause as a disabled account cannot access the system even if Telnet is enabled.

Option B: Incorrect because the Telnet service being disabled would affect all users, not just one administrator.

Option C: " The administrator account has been deleted " is a valid reason as a deleted account cannot log in.

Option D: " The user level of the administrator account has been changed to 0 " is correct. User level 0 typically has insufficient privileges for Telnet access​​.

The configuration provided is for a trunk port, which can carry multiple VLANs.

The command port trunk allow-pass vlan 10 20 30 40 allows tagged traffic from VLANs 10, 20, 30, and 40.

The command port trunk pvid vlan 10 sets the PVID (Port VLAN ID) to VLAN 10.

Any untagged frames received on this port will be assigned to VLAN 10, as per the PVID setting.

Option A (Correct): Since the PVID is VLAN 10, untagged frames are assigned to VLAN 10.

Options B, C, and D (Incorrect): VLANs 20, 30, and 40 are allowed, but untagged frames are not assigned to them.

Thus, the correct answer is A.

Comprehensive Explanation: The interface configuration shows that VLANs 2, 3, and 100 are tagged, meaning frames belonging to these VLANs are transmitted with VLAN tags. VLANs 4 and 6 are untagged, meaning frames for these VLANs are transmitted without tags. The command port hybrid tagged vlan 2 to 3 100 specifies that data frames for VLANs 2, 3, and 100 are transmitted with tags, while port hybrid untagged vlan 4 6 configures the interface to transmit untagged frames for VLANs 4 and 6.

Comprehensive and Detailed In-Depth Explanation:

ESS (Extended Service Set) remains the same across multiple access points (APs) within the same WLAN.

BSS (Basic Service Set) & BSSID (MAC address of AP) change because the STA connects to a new AP.

VLAN may change depending on network policies.

The Full state in OSPF means that all routers have completed LSDB synchronization and formed an adjacency.

If LSDB synchronization is incomplete, the router remains in Loading or Exchange state.

Only after the Database Description (DD) packets, Link-State Requests (LSR), and Link-State Updates (LSU) are exchanged, the router enters the Full state.

Thus, the correct answer is A (TRUE).

Comprehensive and Detailed Explanation:

The history-command max-size command in Huawei VRP (Versatile Routing Platform) is used to set the maximum number of previously used commands that can be saved in the command history buffer.

By default, Huawei devices store 5 previously-used commands in the buffer.

The command history-command max-size 20 increases the buffer size to 20 commands.

This does not limit the buffer to 20 bytes; instead, it allows 20 entire commands to be stored.

The correct statement that matches this behavior is:

" The history-command max-size 20 command sets the maximum of previously-used commands that can be saved in the buffer to 20. "

✅ Reference: HCIA-Datacom Configuration Guide – Command Line Interface

Switches generally operate at the data link layer (Layer 2) and are used to manage communication within a local area network (LAN) by directing traffic among devices. They are not usually deployed as egress devices, which are typically routers. Switches facilitate internal LAN communication, while egress devices handle traffic leaving the network​.

TPID Definition:

TPID (Tag Protocol Identifier) is a field in the Ethernet frame header that indicates the presence of an 802.1Q VLAN tag.

IEEE 802.1Q defines the TPID value as 0x8100.

Why Other Options Are Incorrect:

0x9100: Used in some proprietary protocols but not IEEE standard.

0x8200 and 0x7200: Not valid TPID values.

Comprehensive Explanation: WEP (Wired Equivalent Privacy) is the only security policy in this list that supports open link authentication, which means no actual user credentials are required to associate with the network. WEP uses a shared key for encryption but offers minimal protection and is considered insecure. Other security methods like WPA, WPA2-PSK, and WPA2-802.1X use more secure forms of authentication, requiring credentials such as a password or centralized authentication server.

SNMP Port Numbers:

161: Used for SNMP managers to send requests to agents.

162: Used by SNMP agents to send trap or alarm messages to the Network Management System (NMS).

163 and 164: Not commonly used in SNMP operations.

To determine which types of traffic can be filtered by an advanced Access Control List (ACL) on a Huawei device, we need to understand the capabilities of advanced ACLs as defined in HCIA Datacom documentation and Huawei networking standards. Let’s analyze each option step by step:

Understanding Huawei ACL Types:

Huawei devices support different types of ACLs, including Basic ACLs, Advanced ACLs, and Layer 2 ACLs (MAC-based). Each type has specific filtering capabilities:

Basic ACLs (2000–2999): Filter traffic based on source IP addresses only.

Advanced ACLs (3000–3999): Provide more granular filtering, including source IP addresses, destination IP addresses, protocols, port numbers, and other Layer 3 and Layer 4 parameters. They are more flexible than Basic ACLs but do not filter based on Layer 2 information like MAC addresses.

Layer 2 ACLs (4000–4999): Filter traffic based on source and destination MAC addresses, VLAN IDs, and other Layer 2 parameters.

The question specifically asks about advanced ACLs, so we focus on their capabilities, which are limited to Layer 3 and Layer 4 traffic (IP-based and protocol-specific filtering).

Evaluating Each Option:

A. Network traffic based on a specific source IP address

Advanced ACLs on Huawei devices can filter traffic based on source IP addresses. This is a standard feature of advanced ACLs, which support matching rules for source IP addresses using wildcard masks or specific IP ranges.

This statement is true.

B. Network traffic based on a specific source MAC address

Advanced ACLs operate at Layer 3 and Layer 4 (IP and TCP/UDP) and do not have the capability to filter traffic based on Layer 2 information, such as MAC addresses. Filtering based on MAC addresses requires Layer 2 ACLs (e.g., ACLs in the 4000–4999 range), not advanced ACLs.

This statement is false.

C. Network traffic based on a specific user name

Advanced ACLs do not have the capability to filter traffic based on user names. User-based filtering typically requires authentication mechanisms (e.g., 802.1X, AAA, or RADIUS) combined with dynamic ACLs or policies, not standard advanced ACLs. Advanced ACLs are limited to IP addresses, protocols, and port numbers, not user-specific attributes.

This statement is false.

D. Network traffic based on a specific port number

Advanced ACLs can filter traffic based on transport layer port numbers (e.g., TCP/UDP ports), such as HTTP (port 80), FTP (port 21), etc. This is a key feature of advanced ACLs, allowing granular control over application-layer traffic.

This statement is true.

E. Network traffic based on a specific destination IP address

Advanced ACLs can filter traffic based on destination IP addresses, similar to source IP addresses. This is another standard capability, allowing matching rules for destination IP addresses using wildcard masks or specific IP ranges.

This statement is true.

Conclusion:

Advanced ACLs on Huawei devices can filter traffic based on:

Source IP addresses (Option A).

Destination IP addresses (Option E).

Port numbers (Option D).

They cannot filter traffic based on source MAC addresses (Option B) or user names (Option C), as these require Layer 2 ACLs or authentication-based policies, respectively.

Therefore, the correct answers are A, D, and E.

Switch (A): A network switch is a fundamental device used to connect devices in a local area network (LAN) and forward packets based on MAC addresses.

Firewall (B): A firewall is used to filter and protect the network from unauthorized access and threats.

Router (D): A router is essential for forwarding packets between different networks and managing routing.

Agile Controller (C): This is a network automation and management tool rather than a fundamental networking device. Since it is not typically deployed as a core network device, option C is the correct answer.

Detailed Explanation:RSTP (Rapid Spanning Tree Protocol) employs a synchronization mechanism with the proposal/agreement handshakes to prevent loops during topology changes. By synchronizing states between switches, RSTP avoids temporary loops while quickly transitioning ports to the forwarding state. (Reference: HCIA-Datacom Training Material, RSTP Mechanisms and Synchronization)