H12-811_V1.0 HCIA-Datacom V1.0 Exam Questions and Answers

Comprehensive Explanation: In STP (Spanning Tree Protocol), the Bridge ID (BID) is used to uniquely identify a switch in the network. It consists of a bridge priority and a MAC address. A BID with a bridge priority of 0 and a MAC address starting with 00-01 is reserved for special purposes and cannot be used in a configuration BPDU (Bridge Protocol Data Unit) sent by a regular switch. This prevents conflicts with reserved MAC addresses.

Comprehensive Explanation: In RSTP (Rapid Spanning Tree Protocol), the Alternate Port is the backup path to the root bridge. If the current root port fails, the Alternate Port immediately transitions to the forwarding state, providing a new path to the root bridge with minimal delay. This rapid transition is one of the key improvements of RSTP over the older STP protocol. Backup ports, on the other hand, provide redundancy on the same switch, and edge ports are used to connect directly to end devices.

SNMPv1 uses Trap messages to send unsolicited notifications about network events (e.g., failures, threshold breaches).

Response (A): Sent as a reply to SNMP queries, not proactively.

Get-Next Request (C) and Get-Request (D): These are polling requests, not proactive alarms.

Thus, the correct answer is B (Trap).

Detailed Explanation:In Huawei's VRP (Versatile Routing Platform) command-line interface, when files are deleted using the delete or delete /unreserved command, they are moved to the recycle bin rather than being permanently deleted. To permanently delete these files, they need to be removed from the recycle bin using the reset recycle-bin command​​.

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).

The MAC address table does not contain an entry for 5489-98EC-F011.

When a switch receives a frame with an unknown destination MAC address, it performs flooding.

Flooding sends the frame out of all interfaces except the one it was received on.

A (Incorrect): The switch does not discard unknown frames; it floods them.

B (Incorrect): No request is sent; flooding occurs instead.

D (Incorrect): ICMP is used for network-layer (IP) communication, not Ethernet switching.

Thus, the correct answer is C (Floods the frame on all interfaces except the incoming one).

Understanding the Network Diagram

Host A is in VLAN 10 with a gateway of 10.0.1.254.

Host B is in VLAN 20 with a gateway of 10.0.2.254.

The router (RTA) has two sub-interfaces:

G0/0/1.1 (10.0.1.254/24) for VLAN 10

G0/0/1.2 (10.0.2.254/24) for VLAN 20

The switch (SWA) is using VLAN trunking to forward packets to the router, requiring 802.1Q encapsulation.

One-Armed Routing (Router-on-a-Stick) is being used, meaning a single physical interface (G0/0/1) handles multiple VLANs using sub-interfaces.

Analyzing the Answer Choices

Option A (dot1q termination vid 20) → Incorrect

This command would be configured on G0/0/1.2, not G0/0/1.1.

Option B (dot1q termination vid 30) → Incorrect

VLAN 30 is not part of this topology.

Option C (dot1q termination vid 10) → Correct

Since G0/0/1.1 corresponds to VLAN 10, the correct command is dot1q termination vid 10.

Option D (dot1q termination vid 1) → Incorrect

VLAN 1 is usually the default VLAN, which is not relevant here.

Thus, the correct answer is C (dot1q termination vid 10).

Device Interconnection Requirements:

Device interconnection (such as point-to-point links) requires only two IP addresses: one for each device.

A subnet mask of /30 (255.255.255.252) provides four total addresses (2 usable, 1 network, 1 broadcast).

Efficiency:

Using a /30 subnet avoids wasting IP addresses, making it ideal for point-to-point links.

Why Other Options Are Incorrect:

B (32): /32 is used for single-host IP addresses, not links.

C (24): /24 is excessive for point-to-point links, providing 254 usable addresses.

D (16): /16 provides 65,534 addresses, which is highly inefficient.

References: HCIA-Datacom V1.0 Certification Guide, Chapter 3: IP Addressing.

Comprehensive Explanation: The output shows that the current and next startup configurations are different. Specifically, the startup saved-configuration file is flash:/vrpcfg.zip, and the next startup saved-configuration file is flash:/backup.zip, indicating that changes have been made and the system will use a different configuration file at the next reboot​

VLAN Assignment Overview:VLAN (Virtual Local Area Network) assignment is a critical step in campus network planning. It involves logically segmenting a network to improve manageability, security, and performance. Huawei recommends various approaches based on specific needs.

Analysis of Options:

Option A: "VLAN assignment by service type"This method groups devices based on the type of service they require (e.g., voice, video, data). It helps in isolating traffic for different service types, improving QoS and security. This is a common practice in network planning​​.

Option B: "VLAN assignment by logical area"Logical area-based assignment groups devices based on their logical function in the network (e.g., core, access, distribution). It ensures proper segmentation and alignment with network topology​.

Option C: "VLAN assignment by geographic area"Assigning VLANs based on geographic areas (e.g., floors in a building, departments) helps localize traffic within a region, reducing unnecessary cross-network traffic​​.

Option D: "VLAN assignment by personnel structure"While this option suggests assigning VLANs based on organizational structure (e.g., employees, managers), it is not a typical practice in VLAN assignment. It lacks scalability and alignment with network topology, making it an inefficient approach​.

Correct Answers:The valid VLAN assignment methods in campus network planning are:

A. By service type

B. By logical area

C. By geographic area

Comprehensive and Detailed Explanation:

vlan batch 10 20 → Creates 2 VLANs (10 and 20). ✅

vlan batch 10 to 20 → Creates VLANs 10 to 20 (11 VLANs total). ✅

✅ Reference: HCIA-Datacom VLAN Configuration Guide

A "Length/Type" field value of 0x0806 indicates an ARP (Address Resolution Protocol) frame, which is part of the Ethernet II frame standard. The source MAC address cannot be a broadcast address (FFFF-FFFF-FFFF), as ARP requests are sent from specific hosts. This field helps identify the protocol type used by the Ethernet frame​.

Comprehensive Explanation: The PVID (Port VLAN ID) is the VLAN to which untagged data frames are assigned on a hybrid port. In this configuration, the port hybrid untagged vlan 4 6 command indicates that VLANs 4 and 6 are untagged, and the PVID will be the lowest untagged VLAN, which is VLAN 4. Tagged frames for VLANs 2, 3, and 100 will be forwarded as tagged, but untagged traffic will belong to VLAN 4 by default.

Detailed Explanation:If the username does not contain the delimiter "@" followed by a domain name, the user is automatically assigned to the default domain. In this case, since the username "huawei" does not specify a domain, the user belongs to the default domain​​.

Comprehensive and Detailed Explanation:

BPDU (Bridge Protocol Data Unit) packets are exchanged only on ports in Blocking, Listening, and Learning states.

Ports in Forwarding state DO NOT receive BPDU packets (BPDUs are only processed by non-designated ports).

If a forwarding port starts receiving BPDUs, it goes back to Listening state to re-evaluate STP topology.

✅ Reference: HCIA-Datacom Switching Guide – STP Port States

The command defines a static route to the network 10.0.12.0 with a 255.255.255.0 subnet mask, using 192.168.1.1 as the next-hop address. Static routes are manually set routes with fixed paths, and by default, they have higher priority than dynamic routes, but the specific preference value depends on configuration. This setup enables targeted routing for traffic towards the specified destination​.

Detailed Explanation:APs can be added to an AC using multiple methods. You can add them when they are online, offline, or allow the AC to automatically discover them. Additionally, unauthorized APs can be manually confirmed for security​.

Router Initialization:

When a router boots up, it attempts to load its configuration file from the default save directory to initialize.

If the configuration file is missing, the router defaults to preconfigured parameters to ensure basic functionality.

Default Parameters:

These parameters include IP routing, interface defaults, and system-level settings. They allow network administrators to connect and manually configure the router.

Why Other Options Are Incorrect:

B: The "initial configuration file" refers to the manually created file, which may not exist.

C: The "current configuration file" is used during runtime but does not persist through reboots if unsaved.

D: A "new configuration file" must be manually created and does not exist by default.

References: HCIA-Datacom V1.0 Certification Guide, Chapter 2: Device Initialization.

Detailed Explanation:In a Layer 2 WLAN, an Access Controller (AC) typically handles authentication and management but does not act as a gateway. Instead, a Layer 3 device, such as a router, serves as the gateway. (Reference: HCIA-WLAN Training Material, WLAN Layer 2 and Layer 3 Concepts)

TPID (Tag Protocol Identifier) is a field in the VLAN tag that identifies 802.1Q-tagged frames.

The correct TPID value for 802.1Q is 0x8100.

0x9100 (B) is used for Q-in-Q (double tagging).

0x7200 (A) and 0x8200 (D) are incorrect values.

Thus, the correct answer is C (0x8100).

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.

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​​.

Comprehensive and Detailed Explanation:

Huawei's Versatile Routing Platform (VRP) supports various shortcut keys for efficient command-line navigation:

CTRL+Z → Moves the user back to User View from any configuration mode. ✅

Left Cursor Key (←) → Moves the cursor one character left. ✅

CTRL+C → Stops the execution of a command. ✅

Incorrect Option:

TAB → Does not display the latest command; instead, it auto-completes commands. ❌

✅ Reference: HCIA-Datacom Command Line Guide – CLI Keyboard Shortcuts

Comprehensive and Detailed Explanation:

Link Aggregation (LACP - IEEE 802.3ad):

Combines multiple physical links into a single logical link.

Provides load balancing and redundancy in case a link fails.

Stacking Technology:

Multiple switches are combined into a single logical unit, improving redundancy and simplifying management.

If one switch in the stack fails, others continue functioning without disrupting the network.

Both technologies significantly enhance network reliability, especially in campus networks, ensuring minimal downtime and higher availability.

✅ Reference: HCIA-Datacom Network Principles Guide – Chapter on Link Aggregation & Stacking

B (Correct) - HTTP: Uses TCP port 80 for web traffic.

C (Correct) - FTP: Uses TCP ports 20/21 for file transfer.

A (Incorrect) - TFTP: Uses UDP port 69, not TCP.

D (Incorrect) - Ping: Uses ICMP, which is neither TCP nor UDP.

Thus, the correct answers are B and C.

Huawei AR G3 series routers support all SNMP versions (v1, v2c, and v3) by default.

SNMPv3 provides enhanced security features compared to SNMPv1 and SNMPv2c.

Thus, the correct answer is A (TRUE).

Routing Table and Equal-Cost Routes:When multiple routes to the same destination network have the same cost (e.g., metric or administrative distance), they are referred to as "equal-cost routes." Routers use load balancing to distribute traffic across these routes​​.

Analysis of Options:

Option A: "Sub-optimal routes" are routes that are not preferred due to higher cost or less desirable metrics.

Option B: "Multipath routes" is a general term but does not specify equal cost, making it less precise.

Option C: "Equal-cost routes" is correct as the scenario specifies the same destination network with the same cost.

Option D: "Default routes" are used when no specific route matches the destination, which is unrelated to the given scenario​.

Correct Answer:The routes are C (Equal-cost routes).

Trunk Interface Basics:

Trunk interfaces are used to carry traffic for multiple VLANs between switches.

Tagged frames include VLAN identifiers, while untagged frames belong to the native VLAN.

Untagged Frames:

Frames from the native VLAN are sent untagged on the trunk interface.

Conclusion:

Trunk interfaces support both tagged and untagged frames, so the statement is TRUE.

References: HCIA-Datacom V1.0 Certification Guide, Chapter 4: VLAN Basics.

Direct Route (C): This has the highest priority because it represents networks directly connected to a router’s interfaces.

Static Route (B): These are manually configured but have lower priority than direct routes.

OSPF Route (D): OSPF dynamically learns routes and assigns them based on cost, but it has lower priority than direct and static routes.

RIP Route (A): RIP has the lowest priority due to its high administrative distance (120).

Priority order (from highest to lowest):Direct Route > Static Route > OSPF Route > RIP Route.

Thus, the correct answer is C (Direct Route).

Step 1: Understanding MAC Address Table Lookup

When Host A sends a frame with MAC-B as the destination, SWA checks its MAC address table to determine the correct port to forward the frame.

According to the MAC table, MAC-B is associated with interface G0/0/2.

Step 2: Forwarding Behavior

Since SWA knows the destination MAC address and its associated interface, it will forward the frame only through G0/0/2.

Step 3: Analyzing the Answer Choices

Option A (Correct - Forwards only through G0/0/2): ✅

SWA correctly forwards the frame to G0/0/2, where HostB is connected.

Option B (Incorrect - Forwards through G0/0/3): ❌

MAC-B is not associated with G0/0/3, so the switch will not forward the frame there.

Option C (Incorrect - Floods the frame): ❌

Flooding occurs only when the MAC address is unknown, but in this case, MAC-B is known.

Option D (Incorrect - Discards the frame): ❌

The switch only discards frames if there’s a security violation or filtering rule, which is not mentioned here.

Comprehensive Explanation: The Transport layer (Layer 4) in the OSI model is responsible for end-to-end error checking, flow control, and reliable data transmission. It ensures that data is properly sequenced, without errors, and flow-controlled between the sender and receiver. Protocols such as TCP (Transmission Control Protocol) operate at this layer, providing mechanisms for retransmitting lost packets and maintaining the reliability of a session​​​

How Routers Handle Packets:

Routers do not change the destination IP address when forwarding packets.

The destination IP remains the same to ensure the packet reaches the intended recipient.

Router’s Role:

Routers inspect the destination IP, determine the best path using routing tables, and forward the packet accordingly.

Conclusion:

The destination IP address remains unchanged; hence, the statement is FALSE.

References: HCIA-Datacom V1.0 Certification Guide, Chapter 2: IP Forwarding.

Detailed Explanation:The address 145.4.2.55/26 is a valid unicast address and falls within the range of usable IP addresses for a /26 subnet. The address 237.6.1.2/24 is from a reserved range, 127.3.1.4/28 is part of the loopback range (127.0.0.0/8), and 192.168.10.112/30 only provides two usable addresses, which would not allow the router to be properly configured .

Eth-Trunk Functionality:An Eth-Trunk interface can operate as both a Layer 2 and Layer 3 interface depending on the configuration. For example:

As a Layer 2 interface, it can aggregate Ethernet links for switching.

As a Layer 3 interface, it can aggregate links for routing​.

Correct Answer:FALSE. Eth-Trunk interfaces can function as both Layer 2 and Layer 3 interfaces.

LACP Active Interface Election Overview:In LACP mode, active interfaces are elected based on interface priorities. If the interface priorities are identical, the system compares the interface numbers, and the one with the smaller number is preferred.

Analysis of Options:

Option A: Incorrect because interface priorities alone are insufficient when multiple interfaces share the same priority.

Option B: Device priorities are not used in this scenario for selecting active interfaces.

Option C: Correct. This process aligns with the behavior described for LACP, where interface priorities are compared first, and interface numbers are used as a tie-breaker.

Option D: Incorrect because interface numbers are only used as a secondary criterion.

Correct Answer:C. Interface priorities are compared first. If priorities of interfaces on the Actor are the same, interfaces with smaller interface numbers are elected as active interfaces​​.

IPv6 Anycast Address Characteristics:

Option A: True. Packets are delivered to the nearest interface based on routing distance.

Option B: False. Anycast addresses are not designed for load balancing.

Option C: True. Anycast addresses share the same address space as unicast.

Option D: True. Anycast provides redundancy by allowing multiple endpoints to share the same address​​.

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​.

The BSSID (Basic Service Set Identifier) serves as the MAC address identifier for each Virtual Access Point (VAP) on an AP. Each BSSID uniquely identifies an SSID on a specific radio of an AP, allowing clients to associate with the correct access point in a multi-AP environment​.

Comprehensive Explanation: Netstream is a protocol for flow-based network traffic analysis, not a method for logging into a VRP system. The valid methods for accessing the VRP system include Telnet, Web, and SSH, which are used for remote management and configuration of network devices​

Detailed Explanation:MAC addresses that start with the first octet having the least significant bit (LSB) of the first byte set to 1 (such as 01-02-03-04-05-06) are multicast MAC addresses, and these cannot be assigned to a host's network interface card (NIC). Only unicast MAC addresses can be assigned to hosts​.

Comprehensive and Detailed Explanation:

802.11n operates on both 2.4 GHz and 5 GHz bands (Dual-band support). ✅

802.11ax (Wi-Fi 6) supports 6 GHz (but 802.11n does not). ❌

✅ Reference: HCIA-Datacom Wireless Guide – 802.11 Standards

Detailed Explanation:

Option B: OSPF supports triggered updates, allowing routing tables to be updated only when changes occur, conserving bandwidth.

Option D: OSPF supports area division, which is essential for optimizing large networks and limiting the scope of link-state advertisements.

Option A is incorrect because OSPF calculates the shortest path based on cost, not hop count.

Option C is incorrect; OSPF prevents routing loops by maintaining a loop-free topology through its link-state database.

(Reference: HCIA-Datacom Training Material, OSPF Features)

Comprehensive Explanation: In Telnet sessions, different privilege levels determine what actions a user is allowed to perform. If users are not able to configure the IP address, it is likely that their privilege level is set incorrectly. The administrator must ensure that the Telnet users are assigned the correct privilege level (typically level 15 for full administrative rights) to allow configuration changes, including IP address modifications.

Network Layers in Campus Design:

The three common layers in a campus network are:

Core Layer: Provides high-speed backbone connectivity.

Aggregation Layer: Consolidates traffic and applies policies.

Access Layer: Connects end devices like PCs and phones.

Why "Network Layer" Is Incorrect:

"Network layer" is not a term used to describe physical or logical architecture in campus networks. It refers to Layer 3 in the OSI model, which is about IP routing.

Why Other Options Are Correct:

Core, access, and aggregation layers are widely used in hierarchical network design.

References: HCIA-Datacom V1.0 Certification Guide, Chapter 4: Campus Network Design.

Comprehensive Explanation: Router A needs a static route to reach the Loopback interface (10.0.2.2/32) on Router B. The correct next-hop IP address is 10.0.12.2, which is Router B's interface IP address directly connected to Router A​

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In trunk mode, the interface can forward frames tagged with VLANs specified in the allow-pass list (here, VLAN 100) without removing tags. However, if an untagged frame is received, it is assigned to the PVID (here, VLAN 200). This configuration allows both tagged and untagged traffic, with the PVID determining the VLAN for untagged frames​.

DHCP (Dynamic Host Configuration Protocol) can allocate various network parameters, including:

IP address: Assigns a unique IP to each client.

Gateway address: Provides the default gateway for routing traffic.

DNS server address: Allows domain name resolution. The DHCP server does not assign an operating system, as this is outside its scope​.

Detailed Explanation:The 802.11ax standard, also known as Wi-Fi 6, supports theoretical speeds over 5 Gbit/s and is designed for high-efficiency wireless networking in dense environments. (Reference: HCIA-WLAN Training Material, IEEE 802.11 Standards)

Comprehensive Explanation: OSPF (Open Shortest Path First) is a link-state routing protocol. It builds a complete map of the network's topology using Link-State Advertisements (LSAs) and makes routing decisions based on this map. Protocols like Static and Direct are not dynamic routing protocols, while FTP is a file transfer protocol

In VRP, to enter the configuration view for a specific OSPF area, the syntax [Huawei-ospf-1] area 0.0.0.0 is used. This command specifies Area 0 in the correct format (dotted decimal notation) as required by VRP, which supports OSPF multi-area configuration by designating specific area views​.

Detailed Explanation:In a tree topology, nodes are arranged hierarchically with root nodes at the top and leaf nodes at the base. This structure is often used in larger networks because it supports scalability and easy addition of nodes. However, if a higher-level node (e.g., root or intermediate node) fails, all dependent nodes in its subtree lose connectivity. Therefore, faults at higher layers have a more significant impact than faults at the leaves. (Reference: HCIA-Datacom Training Material, Network Topology Types)

The Forward Delay timer in STP helps prevent temporary loops by setting a delay for ports transitioning through Listening and Learning states before reaching the Forwarding state. This wait period ensures that all switches have updated topology information, reducing the risk of broadcast storms or loops​.

Detailed Explanation:To manage a router in a remote branch office, Telnet is a suitable option as it allows remote access over a network. Unlike a console connection, which requires physical access, Telnet enables remote management as long as the administrator has network connectivity to the router. FTP is used for file transfer, and DHCP is used for dynamic IP address allocation, not for management​​.

The IPv4 header length is variable and is determined by the Header Length (IHL) field in the IPv4 header.

Minimum header size: 20 bytes (5 x 4B) → No options field.

Maximum header size: 60 bytes (15 x 4B) → Includes maximum options.

Option A (Incorrect - 64B): The maximum possible length of an IPv4 header is 60B, so 64B is not possible.

Option B (Correct - 20B): This is the standard IPv4 header size without options.

Option C (Correct - 60B): This is the maximum IPv4 header size with options.

Option D (Correct - 32B): This is a possible IPv4 header size with some options.

Thus, the correct answer is A (64B).

Dynamic IGP Routing Protocols:

OSPF (Open Shortest Path First): A dynamic IGP that uses link-state information for routing within an autonomous system​​.

Analysis of Options:

Option A: "Static" refers to manually configured routes, not dynamic.

Option B: "BGP" is a dynamic routing protocol but an EGP, not an IGP.

Option C: "Direct" refers to routes learned from directly connected networks and is not dynamic.

Option D: "OSPF" is a dynamic IGP, making it the correct choice.

Correct Answer:The dynamic IGP routing protocol is D (OSPF).

The default Link Aggregation Control Protocol (LACP) system priority on Huawei switches is 32768. This priority helps determine which device takes the active role in link aggregation when multiple switches are involved. A lower value indicates a higher priority for managing the aggregated link​.

Comprehensive Explanation: Fit APs (Access Points) are designed to work in conjunction with an Access Controller (AC). They rely on the AC for configuration, management, and control of their wireless services. Without an AC, a Fit AP cannot function independently or provide wireless services. This is in contrast to Fat APs, which have their own management capabilities and can operate independently.

Comprehensive Explanation: In STP, the switch with the lowest Bridge ID is selected as the root bridge. The Bridge ID consists of the bridge priority and the MAC address. In this case, the switch with the bridge priority of 4096 has the lowest Bridge ID, making it the root bridge. If two switches have the same bridge priority, the MAC address is used to break the tie, with the lower MAC address winning.

In STP, the root bridge is elected based on the lowest bridge priority. If there is a tie in bridge priority, the device with the lowest MAC address is selected as the root bridge. This process ensures a stable, predictable root bridge selection in the network​.

Detailed Explanation:The Time to Live (TTL) field in an IP packet is decremented by 1 each time the packet passes through a router. When the TTL reaches zero, the packet is discarded to prevent it from circulating indefinitely. (Reference: HCIA-Datacom Training Material, IP Packet Structure)

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.

Detailed Explanation:UDP (User Datagram Protocol) is a connectionless protocol that does not provide reliability, packet sequencing, or traffic control. These features are usually managed by TCP, which is used for applications requiring reliable data transmission. UDP’s design makes it suitable for real-time applications, such as video streaming or VoIP, where speed and low latency are prioritized over reliability. (Reference: HCIA-Datacom Training Material, UDP Characteristics)

Detailed Explanation:LSAs (Link-State Advertisements) are the fundamental OSPF messages used to convey network topology information. LSU (Link-State Update), LSR (Link-State Request), and LSACK (Link-State Acknowledgment) are all types of messages related to OSPF's operations, but "LSA" alone is not a valid OSPF message type​.

Detailed Explanation:Making a call on a landline telephone involves network communication. Though it uses a traditional telephone network (Public Switched Telephone Network, PSTN), the process of sending and receiving voice data through a wired system qualifies as network communication. The voice signals are converted into electrical signals, transmitted over the network, and then converted back into voice signals on the receiving end .

Switch Forwarding Behavior:

If the destination MAC is not found in the MAC address table, the switch floods the frame.

Broadcasting Within VLANs:

VLAN tagging ensures the frame remains within its designated VLAN.

The frame is not sent to all interfaces but only within the VLAN.

Why Other Options Are Incorrect:

A: Does not consider VLAN segmentation.

C: Switches do not discard unknown unicast frames unless configured to do so.

D: Includes access interfaces only, but flooding happens on all VLAN interfaces.

Conclusion:

The switch floods the frame within the VLAN, making the correct answer B.

References: HCIA-Datacom V1.0 Certification Guide, Chapter 4: Switch Forwarding Mechanisms.

In Spanning Tree Protocol (STP), Topology Change (TC) BPDUs are used to notify switches about network topology changes.

The Root Bridge generates BPDUs with TC bits set, which are forwarded through the network.

Non-root switches forward these BPDUs through their Designated Ports.

Option A (Incorrect - Root Port): The Root Port receives BPDUs from the Root Bridge but does not forward them.

Option B (Correct - Designated Port): Designated ports are responsible for forwarding BPDUs down the tree towards other switches.

Option C (Incorrect - Backup Port): Backup ports are blocking and do not forward BPDUs.

Option D (Incorrect - Alternate Port): Alternate ports are in a blocking state and do not forward BPDUs.

Thus, the correct answer is B.

An AP (Access Point) radio can support multiple SSIDs, allowing segmentation of different types of traffic on the same wireless network. Each SSID can have unique security and access policies, enabling flexible wireless network configurations for different user groups​.

B (Correct): GE0/0/1 is untagged for VLAN 10, meaning it does not add VLAN tags to VLAN 10 frames.

C (Correct): GE0/0/1 is also untagged for VLAN 20, so it does not add VLAN tags to VLAN 20 frames.

D (Correct): The output shows four VLANs (10, 20, 30, 40), which were manually created.

A (Incorrect): GE0/0/2 is not explicitly mentioned, so VLAN tagging behavior cannot be confirmed.

Thus, the correct answers are B, C, and D.

Main Functions of Routers:Routers primarily operate at the Network Layer (Layer 3) of the OSI model, forwarding data packets based on destination IP addresses and maintaining routing tables for decision-making.

Analysis of Options:

Option A: "Routers forward data packets based on source IP addresses" is incorrect, as routers use the destination IP address in a packet to determine its forwarding path, not the source IP address​​.

Option B: "Routers enable devices on the same network segment to communicate with each other" is not a function of routers. Devices on the same segment communicate using switches or hubs, which operate at the Data Link Layer (Layer 2)​​.

Option C: "Routers forward data packets according to routing tables" is a correct function, as routers rely on routing tables to determine the best path for forwarding packets.

Option D: "Routers learn routes through multiple routing protocols and add them to the routing table" is a correct function of routers in dynamic routing scenarios​.

Correct Answer:The functions A and B are not main functions of routers.

Comprehensive and Detailed Explanation:

The first command:

ip route-static 10.1.1.0 24 12.1.1.1 permanent

Sets a static route to 10.1.1.0/24 via next-hop 12.1.1.1 and marks it permanent (remains in the table even if unreachable).

The second command:

ip route-static 10.1.1.0 24 13.1.1.1

Configures a backup route to 10.1.1.0/24 via next-hop 13.1.1.1.

This route only becomes active if the primary route (12.1.1.1) fails.

✅ Reference: HCIA-Datacom Routing Guide – Static Route Configuration

Comprehensive and Detailed Explanation:

In OSPF, routers on a broadcast network elect a DR and BDR to reduce overhead.

The multicast address 224.0.0.6 is used exclusively by the DR and BDR to receive LSU packets.

Other routers send LSU packets to 224.0.0.6, and the DR forwards them to 224.0.0.5 (all OSPF routers).

✅ Reference: HCIA-Datacom Routing Guide – OSPF DR/BDR Operations

In the ACL (Access Control List) configuration:

Rule 5: Permits traffic from 192.168.1.1.

Rule 10: Denies traffic from 192.168.1.1.

Since ACLs are processed in sequential order, the first matching rule is applied.

Option A (Incorrect): The first rule (permit) is matched before the deny rule.

Option B (Incorrect): 192.168.1.254 is not listed in the ACL, so it does not match any rule.

Option C (Correct): 192.168.1.1 matches the first permit rule (Rule 5), so it is allowed.

Option D (Incorrect): 192.168.1.254 is not mentioned in the ACL rules, so it does not match the permit rule.

Thus, the correct answer is C.

Detailed Explanation:The protocol number for TCP in the IPv4 header is 6. Since Telnet uses TCP as its transport layer protocol, the protocol field in the IPv4 header will contain the value 6​​.

Detailed Explanation:In manual load balancing mode, all active interfaces forward traffic, distributing it evenly across links without LACP. This allows for static load balancing. Option B is incorrect because LACP (Link Aggregation Control Protocol) is not involved in manual mode. (Reference: HCIA-Datacom Training Material, Link Aggregation and Manual Load Balancing)

Comprehensive Explanation: The wildcard mask 0.0.254.255 corresponds to a range of IP addresses where the second octet can vary between 2 and 4, and the third octet can vary between 0 and 255. This means the ACL rule matches IP addresses in the range 10.0.2.0 to 10.0.4.255. The only option that falls within this range is 10.0.4.5, making it the correct answer.

OSPF does not use TCP or UDP because it has its own reliable transmission mechanisms.

OSPF packets are encapsulated directly in IP packets using protocol number 89.

TCP (A) is used for connection-oriented communication, but OSPF does not rely on it.

UDP (C) is used for connectionless communication, but OSPF does not use it.

HTTP (B) is an application-layer protocol and irrelevant here.

Thus, the correct answer is D (IP).

Detailed Explanation:The priority (preference) of static routes can indeed be manually specified in Huawei devices. By default, static routes have a preference of 60, but this can be changed to create backup routes or prioritize certain routes over others.

Comprehensive and Detailed Explanation:

On Huawei VRP-based devices, the configuration file (vrpcfg.zip) is not immediately deleted when using the delete command.

Instead, it is moved to the recycle bin, ensuring accidental deletions can be recovered.

To permanently delete the file, the user must clear the recycle bin using the reset recycle-bin command.

✅ Reference: HCIA-Datacom Configuration Guide – File Management on VRP

Detailed Explanation:Static routing does not automatically recover from link failures; manual reconfiguration is required if a static route path becomes invalid. Dynamic routing protocols, on the other hand, adapt automatically to network changes, adjusting routes as needed. (Reference: HCIA-Datacom Training Material, Static vs. Dynamic Routing)

Comprehensive and Detailed Explanation:

Huawei controllers support open APIs for network programmability:✅ RESTful → Web-based API using HTTP methods.✅ OpenFlow → SDN protocol for control/data plane separation.✅ NETCONF → XML-based network configuration protocol.

❌ Incorrect Option:

AAA (Authentication, Authorization, and Accounting) is a security mechanism, NOT an open API.

✅ Reference: HCIA-Datacom SDN Guide – Open API Support

Routing preference (administrative distance) is the first criterion used when multiple paths exist.

If multiple routes have the same preference, the router then compares the cost (metric) to choose the best path.

Lower cost values indicate better paths and are preferred by the router.

If multiple paths have the same cost, the router may perform load balancing (depending on the routing protocol).

Thus, the correct answer is A (TRUE).

Detailed Explanation:With SNMP (Simple Network Management Protocol), a Network Management System (NMS) can both monitor device status and configure settings on managed devices using SNMP Set commands. (Reference: HCIA-Datacom Training Material, SNMP Protocol Functions)

Comprehensive Explanation: When a switch port receives an untagged frame, the port adds the default VLAN ID, known as the PVID (Port VLAN ID), to the frame. This ensures that the frame is associated with a specific VLAN before it is forwarded. The PVID represents the VLAN to which the port belongs and is used when the port receives untagged traffic. This behavior is typical for access and hybrid ports in a VLAN-enabled switch configuration.

Detailed Explanation:Local Area Networks (LANs) cover a small geographic area, such as a home or office. They typically connect computers and devices within a limited area, such as a single building. In this case, both a home network and an office network of a company qualify as LANs. On the other hand, a Metropolitan Area Network (MAN) covers a city-wide area, and the Internet is a global network, so these are not LANs .

The telnetlib module in Python provides functions to interact with Telnet servers, allowing Python scripts to automate Telnet sessions. This module is widely used in network automation and scripting tasks, where Telnet is used to access and manage network devices remotely​.

Comprehensive Explanation: In OSPF, an Area Border Router (ABR) is a router that has interfaces in more than one OSPF area, facilitating communication between different areas. If a router has interfaces in only one OSPF area, it is not an ABR. Based on the network structure, it is incorrect to assume that all routers except RTA are ABRs. A router can only be considered an ABR if it has interfaces connecting to multiple OSPF areas. If a router only connects within one area, it is not an ABR.