Huawei H12-811_V1.0 HCIA-Datacom V1.0 Exam Exam Practice Test

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​​.

In a many-to-many non-NAPT (Network Address Port Translation) configuration, each private host requires a unique public IP address from the address pool. If only two public IP addresses are available and both are already in use by Host A and Host B, no IP will be available for Host C, preventing it from accessing the public network​.

In RSTP (Rapid Spanning Tree Protocol), the Backup port serves as a backup for the Designated port on the same bridge segment, not the root port. If the root port fails, the alternate port, not the backup port, takes over to maintain connectivity to the root bridge. The backup port does not have the capability to replace the root port​.

Detailed Explanation:

An edge port in RSTP (Rapid Spanning Tree Protocol) is designed to immediately transition to the forwarding state without participating in the spanning tree calculation. This allows for quicker convergence and is suitable for ports connected to end devices (not to other switches).

PPP (Point-to-Point Protocol) is versatile and allows IP addresses on each end of a link to belong to different subnets. This capability supports flexible WAN (Wide Area Network) connections where different subnet addressing schemes may be required. This flexibility is part of PPP's design, allowing it to function effectively over varied network architectures​.

Private vs Public IPs:

192.168.1.2 belongs to the private IP range (192.168.0.0/16).

Private IP addresses cannot be routed on the Internet and must be translated.

Network Address Translation (NAT):

NAT converts private IP addresses to a public IP so that the device can access the Internet.

Conclusion:

NAT is required to access the Internet from a private IP, making the statement TRUE.

References: HCIA-Datacom V1.0 Certification Guide, Chapter 6: NAT and IP Addressing.

In OSPF networks, a DR (Designated Router) is elected for each broadcast domain, such as each Ethernet segment. Given the topology where there are multiple Ethernet segments, a DR will be elected in each segment, resulting in three DRs based on the configuration and network design​.

In the IP header at the network layer, the Protocol field specifies the transport layer protocol in use. The protocol number for UDP is 17, not 6. Protocol number 6 is reserved for TCP. This field allows IP packets to be correctly processed by the appropriate transport-layer protocol at the receiving device​.

Comprehensive Explanation: In Software-Defined Networking (SDN), the control plane (which makes decisions about where to send traffic) is separated from the forwarding plane (which actually moves packets to their destinations). This separation allows for centralized control and management of the network, enabling programmability and greater flexibility. SDN controllers manage the control plane, while individual switches or routers handle the forwarding of data.

Network Communication Types:

A: Downloading emails is an example of client-server communication.

B: Accessing a website involves HTTP/HTTPS communication.

C: Chatting via instant messaging involves real-time data exchange using protocols like XMPP or WebSockets.

D: Watching online videos involves streaming protocols like HTTP Live Streaming (HLS).

Conclusion:

All options represent common types of network communication between devices.

References: HCIA-Datacom V1.0 Certification Guide, Chapter 7: Network Applications.

IPv6 Address Types:

Unicast: Identifies a single interface.

Anycast: Identifies a set of interfaces, delivering to the nearest one.

Multicast: Delivers to multiple interfaces.

Broadcast: Does not exist in IPv6; replaced by multicast addressing​​.

OSPF Network Types Overview:OSPF (Open Shortest Path First) supports different network types based on the underlying physical or logical topology:

A. Broadcast: OSPF assumes a fully meshed network, like Ethernet. DR/BDR elections occur.

B. Point-to-Point: A simple two-node network where no DR/BDR elections occur.

C. NBMA: OSPF operates over WAN technologies like Frame Relay. DR/BDR elections occur.

D. Point-to-Multipoint: OSPF operates on logically defined topologies where broadcast or multicast is not supported.

OSPF Flexibility:OSPF accommodates all these network types to ensure compatibility with a variety of link-layer technologies.

References: HCIA-Datacom V1.0 Certification Guide, Chapter 6: OSPF Fundamentals.

Comprehensive Explanation: DHCP (Dynamic Host Configuration Protocol) involves several packet types used in the process of assigning IP addresses. These include:

DHCP Discover: The client broadcasts this packet to find available DHCP servers.

DHCP Offer: The DHCP server responds with an IP address offer to the client.

DHCP Request: The client requests the offered IP address from the server.There is no such thing as a "DHCP Rollover" packet. The process continues with the DHCP server sending an acknowledgment to finalize the IP address lease.

Detailed Explanation:In a "one-armed routing" setup, a router with sub-interfaces can handle inter-VLAN routing by logically segmenting traffic within a single physical interface. In this configuration, each department (Administration and Finance) is assigned a different VLAN with separate sub-interfaces on Router R1.

In such a setup, communication between different VLANs (i.e., inter-VLAN routing) is handled by the router, even without Proxy ARP enabled. The router can directly route packets between the VLANs as it is aware of the different networks and performs Layer 3 forwarding based on the IP address of each VLAN's sub-interface.

Thus, even if ARP Proxy is disabled, devices in the Administration and Finance departments can communicate through the router because inter-VLAN routing takes place at Layer 3 without relying on ARP proxy functionality​​​.

Tracert (Traceroute) works by sending packets with progressively higher TTL (Time-to-Live) values, causing them to expire at each router along the path. When TTL expires, the router sends back an ICMP "Time Exceeded" message, which includes the source IP address of that router. This allows Tracert to record the IP addresses of each router on the path to the destination​.

Detailed Explanation:SNMPv3 is the version that focuses on security and administration. It offers features such as strong authentication and encryption to secure network management, along with enhancements in administration such as notifications and proxy forwarding​​.

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​​​

In the provided routing table, the router’s next hop for each destination indicates whether the destination is reachable directly or indirectly. For entries where the next hop is specified, the router forwards packets accordingly through the designated interface, as confirmed in the table output. This information is used to verify the forwarding behavior for each destination​.

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

Comprehensive Explanation: Hybrid interfaces are capable of carrying both tagged and untagged VLAN frames. They can remove VLAN tags from certain VLANs when sending data frames, depending on the configuration. The command port hybrid untagged vlan x allows a hybrid interface to transmit data frames for VLAN x without a tag, while still tagging other VLANs as required. Hybrid interfaces are flexible and can be used for trunking, but unlike pure trunk ports, they do not always require VLAN tags.

In OSPF, the Backup Designated Router (BDR) is selected based on the highest priority and, in case of a tie, the highest router ID. Given that Router D has the appropriate settings, it is designated as the BDR, providing backup for the DR (Designated Router) in this network configuration​.

Detailed Explanation:In LACP (Link Aggregation Control Protocol), the Actor is elected based on device priority, interface priority, and MAC address. These parameters ensure consistency and determine the active links within the aggregated trunk. The interface number alone is not a determining factor. (Reference: HCIA-Datacom Training Material, Link Aggregation Control Protocol (LACP))

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)

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)

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.

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

Command Overview:The Huawei Versatile Routing Platform (VRP) uses specific commands to manage file systems and view directory contents. While the dir command is used to list files in the current directory, the pwd command is not supported in VRP environments. Instead, the current working directory is displayed as part of the command prompt in VRP​​​.

Command Analysis:

dir Command:This command is supported and displays the list of files and subdirectories in the current directory. Example:

dir

Output includes filenames, sizes, and other metadata.

pwd Command:The pwd command is commonly used in UNIX/Linux systems to print the current working directory. However, this command is not available on VRP. VRP automatically shows the current directory in its prompt, making pwd unnecessary.

Correct Answer:Since only dir is valid, the statement is false. The correct answer is B (FALSE).

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.

Detailed Explanation:In RSTP, there are three port states: Discarding, Learning, and Forwarding. These states replace the five traditional STP states by combining them to optimize network convergence​​.

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.

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.

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​.

A broadcast address, with all host bits set to 1, is used for broadcasting messages to all devices within a network segment. It cannot be assigned to a specific host, as its purpose is to reach every device in the subnet. Therefore, it is reserved for broadcast communication and cannot serve as an individual host address​.

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 Explanation: The IEEE 802.11g standard operates exclusively in the 2.4 GHz frequency band, offering data rates up to 54 Mbps. Other standards, such as 802.11a, operate in the 5 GHz band, while 802.11n and 802.11ax support both 2.4 GHz and 5 GHz frequency bands, making 802.11g the only standard in this list that is limited to 2.4 GHz.

Detailed Explanation:Using DHCP provides several advantages:

It helps prevent IP address conflicts because the DHCP server dynamically assigns IP addresses, ensuring each device gets a unique one.

IP addresses can be reused by setting lease times, allowing the DHCP server to recycle addresses from devices that no longer need them.

Centralized configuration management is also possible. If network configuration details such as the DNS server change, the administrator can update these settings on the DHCP server, and all DHCP clients will automatically receive the new information​​.

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​

Router Functionality:Routers operate at the Network Layer (Layer 3) of the OSI model. They use IP addresses to forward packets between different networks and determine the best path for data transmission based on routing tables​​.

Analysis of Options:

Option A: "Network layer" is correct, as routers are Layer 3 devices.

Option B: "Transport layer" handles end-to-end communication and reliability (e.g., TCP/UDP), not routing.

Option C: "Data link layer" is for local node-to-node data transfer (e.g., MAC addresses), handled by switches.

Option D: "Application layer" is for user-facing software interactions (e.g., HTTP, FTP).

Correct Answer:Routers work at the A (Network layer).

Encapsulation is the process of adding headers and trailers to data at each layer of the OSI model as the data moves from the application layer to the physical layer. Decapsulation is the reverse process when data is received. These processes are critical in implementing network communication, ensuring the proper function of protocols, and assisting in locating faults during data transmission. They do not, however, shorten packet length​

Detailed Explanation:The Type/Length field value of 0x0800 indicates that the upper-layer protocol is IPv4. However, the length of the IPv4 header can range from 20 to 60 bytes, not the length of the entire upper-layer packet. The field refers to the type of the encapsulated protocol, and the length is not constrained to the header alone​​.

Detailed Explanation:A device running Standard Spanning Tree Protocol (STP) is not compatible with Rapid Spanning Tree Protocol (RSTP) BPDUs and will discard them upon receipt. STP devices cannot interpret the additional RSTP fields, leading to discarded BPDUs. (Reference: HCIA-Datacom Training Material, STP and RSTP Compatibility)

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​.

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.

If host A already has host B’s MAC address in its ARP cache, it can send packets directly to host B without needing to perform an ARP request. This cached information allows immediate packet delivery, assuming no network changes have occurred that would invalidate the ARP entry​.

Comprehensive Explanation: It is possible for the load balancing modes at both ends of an Eth-Trunk (Ethernet Trunk) to be different, as long as the devices at both ends support the different modes. Load balancing modes control how traffic is distributed across multiple links in the trunk. Although the modes may differ, they must be compatible in terms of ensuring that traffic is appropriately handled across the multiple physical interfaces bundled in the trunk.

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)

Command Output Overview:

The command display startup is used to check the configuration of the startup system software, configuration files, license files, and other related settings on Huawei routers. The output in this case provides details about:

The current system software (ar2220-v200r003c00spc200.cc).

The next startup system software (ar222b-v200r003c00spc200.cc).

Backup and saved configuration files, which are not defined (null).

Analysis of Options:

Option A: "The system file for next startup cannot be modified."This statement is false because the system file for the next startup can be modified using the startup system-software command. The file path for the next startup system software (ar222b-v200r003c00spc200.cc) indicates that it has been configured and can be changed by the administrator. The command syntax is supported as per Huawei's documentation​​.

Option B: "The startup system software <startup-software-name> command can be used to modify the system software for next startup."This is true and matches the functionality provided by Huawei's routers. The command allows administrators to specify the software package to be used at the next system reboot​​.

Option C: "The running configuration file is not saved."This is true as the Startup saved-configuration file is listed as null, meaning that no configuration file has been saved for startup. Saving the running configuration is necessary to ensure settings persist after a reboot​​.

Option D: "The system file used for the current startup is ar2220-v200r003c00spc200.cc."This is true as per the output under Startup system software, which confirms the system file used in the current boot process​​.

Correct Statement Selection:Based on the analysis, the statement "The system file for next startup cannot be modified" is false. This matches the system's behavior, where administrators are allowed to modify the next startup file using relevant commands.

References:

Huawei HCIA-Datacom V1.0 Training Material and Lab Guide​​.

Command-line operations from Huawei routers, as documented in the training materials and lab environments​​.

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​.

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​.

Detailed Explanation:SNMP-enabled devices can send traps, which are unsolicited messages that notify network administrators of significant events or issues, helping them to detect and resolve problems quickly​.

Detailed Explanation:In NAPT, port numbers are dynamically assigned as traffic flows through the router. The port number range is automatically selected, and manual configuration of each mapping is not required. NAPT dynamically uses different ports for mapping private IP addresses to a single public IP address​​.

Comprehensive Explanation: In STP (Spanning Tree Protocol), the root bridge is elected based on the lowest Bridge ID. The Bridge ID consists of two parts: the bridge priority and the MAC address of the switch. The switch with the lowest Bridge ID is elected as the root bridge. If two switches have the same priority, the switch with the lowest MAC address becomes the root. Other parameters such as Port ID and Root path cost are used in subsequent decisions to determine the best paths to the root bridge, but they are not used in the root bridge election itself.

The command lease day 0 hour 10 sets the lease time for DHCP-assigned IP addresses to 10 hours. This setting provides a short, specific lease duration for dynamically assigned IP addresses, which can be useful in networks where devices frequently join and leave, minimizing IP address retention time​.

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​.

Configuration Analysis:

The router has two DHCP pools (pool1 and pool2).

Interface Gi/0/0 is assigned the IP address 10.10.10.1/24 and is configured to use global DHCP.

Reasoning:

The IP address 10.10.10.1 indicates that the interface belongs to the 10.10.10.0/24 network segment.

DHCP assigns IP addresses based on the network of the interface. Therefore, the host will receive an IP address from pool1 (10.10.10.0/24).

Detailed Explanation:RSTP (Rapid Spanning Tree Protocol) combines the Blocking, Listening, and Disabled states into Discarding, reducing the number of states to Discarding, Learning, and Forwarding. RSTP does not use a separate Listening state, as in standard STP. (Reference: HCIA-Datacom Training Material, RSTP Port States)

Detailed Explanation:Static MAC address entries are manually configured and stored in the switch's configuration file, making them persistent across reboots. These entries remain in the MAC address table after a restart, unlike dynamic entries, which are lost. (Reference: HCIA-Datacom Training Material, MAC Address Table Types)

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​.

The VRP platform does not support configuration through FTP. Configuration methods typically include using a console port, Telnet, or SSH, allowing for direct access to the device configuration. FTP is generally used for file transfer, not direct configuration, and therefore is not a supported method for configuring a router​.

Detailed Explanation:The default preference of static routes on Huawei routers is 0. This means that if a static route is present, it will always take precedence over routes with higher preferences, such as dynamically learned routes, unless a lower preference is manually assigned​​.

Restoring factory defaults on an AR2200 router requires both clearing the current configuration and resetting saved configurations. These steps ensure that any custom settings are removed, reverting the router to its original state. Simply restarting or specifying a startup file without clearing configurations would not remove custom settings​.

Detailed Explanation:When bridge priorities are identical, STP elects the switch with the lowest MAC address as the root. Here, Switch B has the lowest MAC address (00-e0-fc-00-00-10), making it the root switch. (Reference: HCIA-Datacom Training Material, STP Root Bridge Election)

In Huawei devices, advanced ACLs use a number range from 3000 to 3999. These ACLs allow more granular control over traffic by permitting conditions based on source and destination IP addresses, protocol types, and ports, making them suitable for complex filtering requirements​.

TCP (Transmission Control Protocol) uses a three-way handshake process to establish a reliable connection between two devices, ensuring that data transmission is stable and reliable. The handshake sequence (SYN, SYN-ACK, ACK) confirms that both devices are ready to send and receive data, guaranteeing ordered and error-checked delivery. This characteristic makes TCP a reliable transport protocol​.

Understanding Trunk Ports:

Trunk ports carry traffic from multiple VLANs.

Native VLAN (PVID) frames are sent untagged on the trunk.

Breakdown of Configuration:

port link-type trunk → Interface operates as a trunk.

port trunk pvid vlan 10 → Sets VLAN 10 as the native VLAN.

port trunk allow-pass vlan 10 20 30 40 → Allows traffic from VLANs 10, 20, 30, and 40.

Conclusion:

Since VLAN 10 is the PVID (native VLAN), frames from this VLAN are sent untagged.

Correct answer is A (VLAN 10).

References: HCIA-Datacom V1.0 Certification Guide, Chapter 4: VLANs and Trunking.

Detailed Explanation:

The subnet 200.200.200.200/30 allows two usable IP addresses, 200.200.200.201 and 200.200.200.202. These two addresses can communicate with each other directly, without the need for routing .

Detailed Explanation:OSPF (Open Shortest Path First) uses protocol number 89 at the network layer. This distinguishes OSPF packets from other protocols such as TCP (protocol number 6) and ICMP (protocol number 1) .

To form an EUI-64 address, the MAC address is split and FFFE is inserted in the middle, making the EUI-64 format 00E0-FCEF-FFFE-0FEC. Additionally, the 7th bit of the first byte is flipped to form the Modified EUI-64 address used in IPv6 for Stateless Address Autoconfiguration (SLAAC)​.

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:Access Control Lists (ACLs) are processed in sequential order, meaning that once a packet matches a rule, subsequent rules are ignored. To ensure that more specific (strict) conditions are applied, strict rules should be listed first, followed by loose rules. (Reference: HCIA-Datacom Training Material, ACL Configuration and Rule Order)