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

Comprehensive Explanation: On a network consisting of multiple broadcast domains (like Ethernet links), OSPF will elect one DR (Designated Router) and one BDR (Backup Designated Router) per broadcast segment. In this topology, two Ethernet segments are formed, so two DRs will be elected​

SNMP Agent Functionality:Each network device running SNMP includes an agent process that collects and manages information about the device's operations. This process interfaces with the SNMP manager to provide network monitoring and management capabilities​​.

The country-code command is used on an AC (Access Controller) to specify the country code, which aligns the wireless settings with local regulatory standards. Setting the correct country code ensures compliance with regional RF (Radio Frequency) regulations, such as frequency bands and transmission power limits​.

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)​.

Detailed Explanation:

Dynamic routing protocols, such as OSPF and RIP, automatically discover and generate routes, adjusting when network topology changes occur. This helps in reducing the manual configuration required by static routes and ensures that the network adapts efficiently to changes such as link failures or the addition of new routes.

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.

An ARP (Address Resolution Protocol) packet includes several fields essential for mapping IP addresses to MAC addresses. The fields include:

Source Protocol Address: Identifies the IP address of the requesting device.

Source Hardware Address: Contains the MAC address of the source.

Hardware Type: Indicates the hardware type, typically Ethernet.

Operation Code: Specifies the operation (request or reply). These fields collectively allow devices to resolve IP addresses to physical MAC addresses, enabling direct communication within the local network​.

Detailed Explanation:Each Virtual Access Point (VAP) on an AP is identified by a unique Basic Service Set Identifier (BSSID), which is the MAC address used at the data link layer. The SSID is a human-readable network name, while the BSSID is the technical identifier​.

Detailed Explanation:An MPLS (Multiprotocol Label Switching) header includes the following fields:

Label: Identifies the MPLS path.

TTL (Time to Live): Limits the lifetime of the MPLS packet.

EXP (Experimental): Used for QoS marking. The Tos (Type of Service) field is part of the IP header, not MPLS.

(Reference: HCIA-Datacom Training Material, MPLS Header Fields)

Bridge Priority Overview:

Bridge Priority is a key parameter in Spanning Tree Protocol (STP) and is used to elect the root bridge.

The default bridge priority for Huawei switches is 32768, which is the default for many vendors.

How STP Uses Bridge Priority:

Lower bridge priority values are preferred during root bridge elections.

Administrators can modify this value for desired root bridge placement.

References: HCIA-Datacom V1.0 Certification Guide, Chapter 8: Spanning Tree Protocol.

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 .

In Huawei’s VRP, the default preference value for OSPF routes is generally 10, but this value can be adjusted based on configuration requirements. Therefore, it is not necessarily always set to 10, as network administrators may alter the preference to prioritize different routes. This flexibility allows customization based on the network's specific routing needs​.

Comprehensive Explanation: In OSPF (Open Shortest Path First), a router first synchronizes its Link-State Database (LSDB) with its neighbors by exchanging link-state information. Only after this synchronization process is complete does the router transition to the Full state. The Full state indicates that the router has fully converged with its OSPF neighbors and has a complete and up-to-date view of the network topology. Therefore, the router enters the Full state after synchronizing its LSDB, not before.

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)

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​.

An Ethernet II frame has a standard length range of 64 to 1518 bytes, including the Ethernet header. This range accounts for both the minimum frame size (to prevent collisions) and the maximum frame size (to avoid excessive delay). This specification is in line with IEEE 802.3 standards for Ethernet frames​.

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.

Detailed Explanation:The default Router Dead Interval in OSPF is 40 seconds for broadcast and point-to-point networks. This interval defines the time period a router waits to receive hello packets before declaring a neighbor as down. (Reference: HCIA-Datacom Training Material, OSPF Hello and Dead Intervals)

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​.

OSPF Packet Types:

LSA (Link State Advertisement): Contains topology information that routers use to build their LSDB.

LSU (Link State Update): Used to transmit multiple LSAs.

LSR (Link State Request): Requests specific LSAs from a neighbor router.

LSACK (Link State Acknowledgment): Confirms receipt of LSU packets​​.

Correct Packet for Acknowledgment:The LSACK packet is specifically designed to acknowledge LSU packets. Without acknowledgment, the LSU might be retransmitted unnecessarily.

Correct Answer:The OSPF packet used for acknowledgment is D (LSACK).

Detailed Explanation:With a /30 subnet mask, the valid IP range is 192.168.1.0 - 192.168.1.3:

192.168.1.3 is the broadcast address, so it can be a destination.

192.168.1.1 and 192.168.1.2 are host addresses.

255.255.255.255 is the limited broadcast address, which any device can use to reach all hosts on the local network.

(Reference: HCIA-Datacom Training Material, IP Addressing and Subnetting)

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​​.

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​.

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​.

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​​.

MAC Address Analysis:

MAC addresses starting with 01-00-5E are reserved for IPv4 multicast by the IANA.

Why Other Options Are Incorrect:

A: The address is valid and reserved for multicast.

C: Broadcast addresses use FF-FF-FF-FF-FF-FF.

D: Unicast addresses are typically hardware-assigned and do not use this prefix.

References: HCIA-Datacom V1.0 Certification Guide, Chapter 7: Ethernet Basics.

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​.

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).

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)

Detailed Explanation:In Python, the telnetlib module is indeed used to implement the Telnet protocol, providing functionality for interacting with remote devices over Telnet​.

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:To accommodate 26 hosts, the subnet needs at least 30 addresses (including network and broadcast addresses). A subnet mask of 255.255.255.192 provides 64 addresses (2^6 - 2 = 62 usable addresses), which is more than enough to support 26 hosts while also leaving space for additional hosts if needed.

Detailed Explanation:OSPF (Open Shortest Path First) has several key advantages:

It can load balance traffic among equal-cost routes.

OSPF supports hierarchical area structures, allowing for network scalability and reduced routing table sizes.

OSPF supports strong security measures through packet authentication (MD5 or plain text).

It supports Classless Inter-Domain Routing (CIDR), allowing for more efficient IP address allocation and route aggregation.

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​.

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

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​​.

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​.

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​.

Comprehensive Explanation: In STP (Spanning Tree Protocol), ports can be in several states, including:

Discarding: The port is not forwarding traffic, either because it is in a blocking state or not participating in active forwarding.

Listening: The port is processing BPDUs and is preparing to transition to either the learning or forwarding state. No data frames are forwarded during this state.

Forwarding: The port is actively forwarding traffic as part of the active network topology.

The "Disabled" state is not part of the STP protocol but rather represents a port that is administratively shut down or not participating in the STP process.

SNMP Message Types:

get-request: Sent by the NMS to retrieve data from a device.

set-request: Used by the NMS to modify device settings.

get-response: Sent by the device in response to a get-request.

trap: Sent automatically by a device to notify the NMS of an event.

Why "trap" Is Correct:

If a registered event occurs (e.g., interface down, high CPU usage), the device proactively sends a trap to alert the NMS.

Conclusion:

Since traps notify abnormal events, the correct answer is A (trap).

References: HCIA-Datacom V1.0 Certification Guide, Chapter 7: SNMP and Network Monitoring.

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​.

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​.

The default route preference on Huawei VRP places Direct routes at the highest priority, followed by Static routes, then RIP, and finally OSPF. Direct routes are most trusted as they represent directly connected networks, while OSPF, being a dynamic protocol with more administrative distance, is prioritized lower by default​.

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​​.

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​.

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: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: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​​.

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: 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.

In Huawei's Versatile Routing Platform (VRP), pressing Ctrl+Z is a shortcut that takes the user from any configuration view directly back to the user view. This command is useful for quickly navigating out of multiple levels of configuration back to the main user prompt. This feature is part of the VRP interface management commands for efficient system navigation​.

An Access Control List (ACL) serves as a packet filter by defining rules to permit or deny specific traffic types. However, it only affects traffic after being applied to a service module, such as an interface, ensuring that the ACL rules are enforced on traffic traversing that module. Without this application, the ACL will not impact network traffic​.

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​​.

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​​.

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.

Router A would have three TCP connections in this scenario:

One for the Telnet session from host A to router A.

One for the FTP control connection to router B.

One for the FTP data connection to transfer the configuration file. These TCP connections facilitate the remote login and file transfer across the network​.

The basic IPv6 header has a fixed length of 40 bytes. Unlike IPv4, the IPv6 header is streamlined, omitting some fields (like header checksum) and standardizing the header size. This simplification reduces processing overhead, enhancing routing efficiency and scalability for modern networks​.

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.

Comprehensive Explanation: The "-i" parameter in the Ping command on Huawei VRP (Versatile Routing Platform) is used to specify the source IP address for sending an Echo Request (ping) packet. This is useful in cases where the router has multiple interfaces and you want to control which interface is used to initiate the ping. By defining the source IP address, the ping request can be sent from a specific interface on the router, enabling network administrators to test connectivity from that interface.

The default port number for Telnet is 23. This standard port assignment allows Telnet clients to connect to Telnet servers, facilitating remote management and troubleshooting tasks on network devices. Ports are preassigned to services to streamline network communication and reduce conflicts​.

Comprehensive Explanation: The user-interface maximum-vty command is used on Huawei devices to configure the maximum number of simultaneous VTY (Virtual Terminal Line) users who can log in via Telnet. By limiting the number of VTY sessions, the administrator can control how many users are able to access the device at the same time, preventing excessive connections that may overwhelm the device or reduce security.

Detailed Explanation:Small campus networks are characterized by simple architecture, limited user counts, and straightforward network requirements. Wide coverage is typically associated with larger campus or enterprise networks. (Reference: HCIA-Datacom Training Material, Campus Network Characteristics)

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​​.

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​​.

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 Explanation: The quit command is used to return from the system view to the user view in Huawei's VRP (Versatile Routing Platform). This command allows users to exit the current configuration mode and revert to the default user view. For example, when you are in the system view and you want to return to the user view, typing quit takes you back to the initial prompt without saving the current configuration​​.

Impact of Loops in Layer 2 Networks:Loops in a Layer 2 network cause packets to be repeatedly forwarded, leading to broadcast storms, high CPU utilization, and network disruption​​.

Correct Answer:TRUE. Loops can cause broadcast storms on Layer 2 networks.

Comprehensive Explanation: When Router A forwards the packet to Router B, the destination IP address (11.0.12.1) remains unchanged as it is still meant for Host B. However, the destination MAC address changes to MAC-B, which belongs to Host B, since MAC addresses are only used for local network hops​

Comprehensive Explanation: A routing table contains several key elements:

Cost: Also known as metric, this indicates the cost associated with reaching a specific destination, such as the number of hops or link speed.

Next-hop address: This is the IP address of the next device along the route that packets should be forwarded to.

Protocol: The routing protocol (e.g., OSPF, RIP) that determined the route.

Interface: The physical or logical interface through which the router sends packets to reach the destination.

Destination/Mask: The destination network or subnet and the associated subnet mask define the range of IP addresses for which this route is valid. These elements together allow routers to efficiently forward traffic to the correct destinations.