Huawei H12-821_V1.0 HCIP-Datacom-Core Technology V1.0 Exam Practice Test

A is true– MAC authentication often usesPAP or CHAPfor basic password exchange.

B is false– Bydefault, both theusername and password are set to the full MAC addressof the terminal, not just the last 6 digits.

C is true– MAC authentication istransparentto the user and requiresno client softwareon the terminal.

D is true– The authentication system includes:

Terminal(user device),

Access device(AP or switch), and

Authentication server(e.g., RADIUS).

Reference from Huawei HCIP-Datacom-Core Technology Study Guide:

“MAC authentication does not require client-side software. By default, both the user name and password are the complete MAC address in lowercase without delimiters.”

(Chapter: WLAN Security – Section: MAC Authentication Mechanism)

Comprehensive and Detailed Step-by-Step Explanation:

WAN Definition:

A WAN is a large-scale network spanning a wide geographical area, connecting smaller networks such as LANs and MANs.

Use Cases:

WANs are commonly used for interconnecting campus networks, branch offices, and data centers over long distances.

Correct Statement:

The statement accurately describes the purpose and scope of WANs.

When a Huawei firewall receives a packet that does not match any existing session table entry, it discards the packet. This is part of the default firewall policy, which ensures that unrecognized traffic is treated as a potential security risk and blocked. This behavior is vital for preventing unauthorized access and mitigating external attacks. The feature aligns with Huawei's default security strategies as detailed in their firewall operation manuals ​.

When the router ID is configured in both the system view and the BGP view, the router ID in the BGP view takes precedence because BGP-specific configurations override global settings. This ensures that BGP operates with the most relevant configurations ​.

Comprehensive and Detailed Step-by-Step Explanation:

Understanding the ACL Configuration:

ACL Number:3001 is an advanced ACL.

Rule Description:The rule permits ICMP packets with the following criteria:

Source IP:192.168.1.3(host-specific).

Destination IP:192.168.2.0/24(entire subnet).

Analysis of Each Option:

Option A:True. ICMP packets from 192.168.1.3 to 192.168.2.200 (within the subnet) are permitted.

Option B:True. Packets from 192.168.1.2 (not matching the source) are denied by default.

Option C:False. The ACL only permits ICMP packets, not general IP packets.

Option D:True. The ACL is identified by the number 3001.

The forwarding plane of a switch consists of data forwarding hardware, such as line cards or forwarding engines, and is responsible for tasks like encapsulating/decapsulating packets, providing high-speed data channels, and collecting packet statistics. However, main control boards are part of the control plane, not the forwarding plane. This distinction ensures a separation of data forwarding and control functionalities ​.

 Inasynchronous mode, BFD control packets are exchanged periodically to detect faults.

 Indemand mode, once the session is established, BFD stops sending periodic control packets and relies on external mechanisms to verify connectivity.

 Asynchronous mode is the most commonly used mode. However, the Echo function is supported in asynchronous mode, making Option B incorrect ​.

Comprehensive and Detailed Step-by-Step Explanation:

1. Features of Wi-Fi 6:

Wi-Fi 6 (802.11ax) introduces several new technologies to improve network efficiency, reduce latency, and optimize power usage:

OFDMA (Orthogonal Frequency Division Multiple Access):Allows multiple devices to transmit simultaneously, improving concurrency.

TWT (Target Wake Time):Reduces power consumption by scheduling communication times for devices.

High Bandwidth:Supports up to 9.6 Gbps, significantly faster than Wi-Fi 5.

2. Why Zero Latency is Incorrect:

While Wi-Fi 6 reduces latency compared to earlier standards,zero latencyis not achievable due to inherent delays in network communication.

The statement "Realizes zero latency" is misleading and technically inaccurate.

3. Analysis of Each Option:

Option A: Uses OFDMA technology to achieve high concurrency.

Correct (True Statement).

OFDMA is a core feature of Wi-Fi 6 that improves concurrent communication.

Option B: Realizes zero latency, ensuring efficient service running.

Incorrect (False Statement).

Wi-Fi 6 reduces latency but cannot eliminate it entirely.

Option C: Provides high bandwidth, up to 9.6 Gbps.

Correct (True Statement).

Wi-Fi 6 supports a theoretical maximum bandwidth of 9.6 Gbps.

Option D: Uses TWT technology to reduce terminal power consumption.

Correct (True Statement).

TWT schedules communication times, allowing devices to enter low-power states and conserve battery life.

4. Summary:

Thefalsestatement isB, as Wi-Fi 6 does not achieve zero latency.

In Huawei firewalls, the security level of a zone can be reconfigured by an administrator, making the statement that it cannot be changed false. Other statements accurately describe security level restrictions or defaults ​.

The MED (Multi-Exit Discriminator) is an optional, non-transitive attribute used to influence the exit path. MED is considered after attributes such as Local-Preference, AS-Path, and Origin during route selection. By default, if a MED value is missing, it is treated as 0 unless thebestroute med-none-as-maximumcommand is configured to treat it as 4294967295 ​.

Comprehensive and Detailed Step-by-Step Explanation:

iMaster NCE-Campus Overview:

iMaster NCE-Campus is Huawei’s network management platform for managing and controlling campus networks.

It supports user authentication, including STA (Station) authentication, in WLAN environments.

Authentication Modes Supported:

iMaster NCE-Campus integrates with AAA (RADIUS) servers to perform authentication for wireless clients.

Correct Statement:

The platform can function as an authentication server for WLAN STAs.

Option B isfalse. By default, when the aggregate command is usedwithout any options, BGP generates asummary route, andsuppresses the specific routesthat fall under that summary. To advertise both specific and summary routes, you mustexplicitly configurethe detail-suppressed option to control whether specifics are suppressed or not.

Explanation of the other options:

Ais correct: When suppress-policy is specified, only specific routes matching the policy are advertised; others are suppressed.

Cis correct: The summary automatic command causes summarization based on classful boundaries, which is a legacy behavior.

Dis correct: With detail-suppressed, only the summary route is advertised, not specific prefixes.

Reference from Huawei HCIP-Datacom-Core Technology Study Guide:

“The aggregate command suppresses specific routes by default unless explicitly configured otherwise. Use of suppress-policy or detail-suppressed allows control over which routes are advertised.”

(Chapter: BGP Advanced Features – Section: Route Aggregation)

Understanding the LSDB and Level-2 DIS Election in IS-IS:

In IS-IS, theDesignated Intermediate System (DIS)is elected for both Level-1 and Level-2 on broadcast networks to manage the link-state database (LSDB) and reduce the number of LSAs exchanged.

The election of the DIS is based on thehighest priority. If the priority is the same, the router with thehighest System IDbecomes the DIS.

HCIP-Datacom-Core Technology Training Material (IS-IS DIS Election)​​.

Analyzing the LSDB:

From the LSDB ofR1, the Level-2 link-state database includes the following entries:

LSPID 0100.0000.3003.00-00: This is R3, and it is present in the Level-2 LSDB with the sequence number and checksum details.

Other routers (R1, R2, R4) are present but do not have the characteristics of the Level-2 DIS in this topology.

Based on the System IDs,R3 (0100.0000.3003)has the highest System ID, making it theLevel-2 DIS.

Conclusion:

The Level-2 DIS on the network isR3, based on the election rules and the LSDB information shown in the figure.

 GRE Characteristics

GRE doesnotinherently support encryption or authentication. It is a tunneling protocol for encapsulating packets, and data security features must be implemented using other protocols such as IPsec.

Other correct attributes of GRE include:

B.Supports multicast transmission.

C.Acts as a Layer 3 VPN encapsulation technology.

D.Can work with VPN protocols like IPsec for better security.

 HCIP-Datacom-Core Reference

GRE features and limitations are discussed in VPN encapsulation technology chapters​​.

Comprehensive and Detailed Step-by-Step Explanation:

1. Overview of BGP:

BGP (Border Gateway Protocol) is an Exterior Gateway Protocol (EGP) designed to exchange routing information between different Autonomous Systems (ASs) on the internet. Unlike traditional distance-vector protocols (like RIP), BGP is considered a path-vector protocol, as it not only determines reachability but also ensures policy-based routing decisions and advanced path selection mechanisms.

2. Analysis of Each Option:

Option A: BGP does not support authentication. Therefore, it cannot ensure network security.

This statement isincorrect.

BGP supports authentication using mechanisms such as TCP MD5 (Message Digest 5) and TCP-AO (Authentication Option). These authentication mechanisms ensure that BGP messages are not tampered with or intercepted during transmission, enhancing network security.

HCIA-Datacom Study Guide, Chapter "BGP Concepts and Features," Authentication Section.

Option B: BGP uses TCP as the transport layer protocol.

This statement iscorrect.

BGP relies on TCP (Transmission Control Protocol) as its transport layer protocol, specifically on port 179. TCP provides reliable delivery of BGP messages and ensures the session remains established in case of transient network issues.

TCP also handles error recovery and sequencing, making it a suitable choice for BGP, which requires reliable communication between peers.

In PIM-DM (Protocol Independent Multicast - Dense Mode), the SPT (Shortest Path Tree) establishment process involves flooding to propagate multicast traffic across the network, prune messages to stop sending multicast traffic to unwanted interfaces, and graft messages to re-establishforwarding when needed. State-refresh is not directly involved in SPT establishment but helps maintain the prune state ​.

Routing policies are used to control how routes are imported, advertised, or received. Policy-Based Routing (PBR) is used to forward packets based on policies, bypassing the routing table. Routing policies are not used for packet forwarding ​.

 ACL Matching in Huawei Routers:

Access Control Lists (ACLs) are used to filter packets based on specific criteria, such as source/destination IP, ports, or protocols.

When a packet arrives, the Huawei router processes it against the configured ACL rules to decide whether to permit or deny the packet.

This statement isfalsebecauseIGMPv2 improves upon IGMPv1 by introducing the Leave Group message.

InIGMPv1, members leave silently, and the router waits for the timeout.

InIGMPv2, a host sends aLeave Groupmessage, prompting the router to send aGroup-Specific Queryto determine if other members are still present. If no responses are received, the group is pruned before timeout.

Reference from Huawei HCIP-Datacom-Core Technology Study Guide:

“IGMPv2 allows group members to actively send Leave messages, reducing unnecessary forwarding delays. This improves efficiency over IGMPv1.”

(Chapter: Multicast Protocols – Section: IGMP Versions)

Comprehensive and Detailed Step-by-Step Explanation:

Analysis of VRRP Configuration:

Option A (Preemption):Correct. The output explicitly states that preemption is enabled.

Option C (Authentication):Correct. Authentication is enabled using MD5.

Option D (Group ID):Correct. The VRRP group ID is explicitly stated as 1.

False Statement:

Option B (mVRRP Group):The output does not indicate this is anmVRRP (Multicast VRRP)group. This feature must be explicitly configured and is not enabled by default.

Comprehensive and Detailed Step-by-Step Explanation:

BGP ConnectRetry Timer:

The ConnectRetry timer is used when establishing a TCP connection between BGP peers.

If the connection is successful, the timer is disabled.

If the connection fails, the timer restarts, and the router attempts to reconnect after the timer expires.

Behavior:

This timer prevents excessive connection attempts and ensures efficient resource utilization.

 Neighbor Discovery Protocol (NDP):

NDP is a key protocol in the IPv6 protocol suite, replacing ARP (Address Resolution Protocol) in IPv4.

It operates using ICMPv6 (Internet Control Message Protocol for IPv6) and is critical for managing interactions between IPv6 nodes on the same link.

HCIP-Datacom-Core Technology Training Material (NDP Functions and Features)​​.

 NDP Features and Functions:

A. Address resolution:NDP resolves IPv6 addresses into MAC addresses, similar to ARP in IPv4. It uses Neighbor Solicitation (NS) and Neighbor Advertisement (NA) messages for this purpose.Reference:HCIP-Datacom-Core Technology Training Material (Address Resolution in IPv6)​.

B. Neighbor state tracing:NDP tracks the state of neighbors to determine their reachability. It maintains a neighbor cache and uses NS/NA messages to verify whether neighbors are reachable.Reference:HCIP-Datacom-Core Technology Training Material (Neighbor Reachability in IPv6)​.

C. Duplicate address detection (DAD):NDP ensures that IPv6 addresses are unique within a network. Before assigning an address to an interface, DAD is used to verify that no other node is using the same address. This is done via NS messages.Reference:HCIP-Datacom-Core Technology Training Material (IPv6 Address Assignment and DAD)​.

D. Redirection:NDP provides redirection functionality to inform hosts of a better first-hop router for reaching a particular destination. It uses ICMPv6 Redirect messages for this purpose.Reference:HCIP-Datacom-Core Technology Training Material (NDP Redirect Functionality)​.

 Conclusion:NDP supports all the mentioned functions and features:Address resolution,Neighbor state tracing,Duplicate address detection, andRedirection, making it indispensable for IPv6 networks.

Comprehensive and Detailed In-Depth Explanation:

Type 7 LSAs (NSSA External LSAs)are used inNot-So-Stubby Areas (NSSAs)to carry external routing information.

These LSAs aregenerated only by ASBRs within an NSSA, and later converted toType 5 LSAsby theABR.

Stub areas do not allow ASBRs, meaningType 7 LSAs cannot exist in a stub area.

The question incorrectly states thatType 7 LSAs can be generated in stub areas, which isfalse.

????Reference:Huawei HCIA-Datacom Study Guide, OSPF LSA Types and Area Configurations.

IGMPv1 supports general queries but does not define a Leave message. IGMPv2 introduces the Leave message type, which allows hosts to notify routers when they wish to leave a multicast group, improving efficiency. These distinctions align with the functionality of IGMP versions ​.

ICMPv6 messages are classified into two types: error messages (e.g., Destination Unreachable, Time Exceeded) and informational messages (e.g., Echo Request, Echo Reply). This classification is fundamental to ICMPv6's operation ​.

The virtual MAC address for a VRRP virtual router is determined by the formula00-00-5E-00-01-[VRID in hexadecimal]. For VRID 3, the hexadecimal equivalent is03. Thus, the virtual MAC address is00-00-5E-00-01-03​.

Comprehensive and Detailed Step-by-Step Explanation:

1. Understanding the IGMP Group Entry:

The IGMP group entry contains key information about multicast groups on the interface:

Group Address (225.1.1.2):The multicast group address that the user has joined.

Last Reporter (10.1.6.10):The IP address of the last host that sent an IGMP Report message for this group.

Uptime:The duration since the group was first reported.

Expires:The remaining time before the group entry ages out if no further reports are received.

2. Analysis of Each Statement:

Option A: This entry can be used to construct the corresponding (S, G) entry.

Incorrect.

This is a group entry for IGMP, which contains information about the group (G) but does not include a specific source (S). (S, G) entries are created in PIM (Protocol Independent Multicast), not IGMP.

Option B: This entry is created when the device receives an IGMP Join message from a user.

Correct.

IGMP Join messages are used by hosts to signal their intent to join a multicast group. When such a message is received, the group entry is created.

Option C: Expires indicates the aging time of the IGMP group.

Correct.

The "Expires" field shows the remaining time before the group entry ages out if no further IGMP reports are received.

Option D: 225.1.1.2 is the address of the group that the user joins.

Correct.

The "Group Address" field explicitly states that 225.1.1.2 is the multicast group that the user has joined.

3. Summary:

Correct Options:B, C, D

Comprehensive and Detailed Step-by-Step Explanation:

Single-Hop BFD:

Single-hop BFD is used for detecting link failures in directly connected devices.

It usesUDP port 3784for communication.

Multi-Hop BFD:

For multi-hop scenarios, BFD usesUDP port 4784to ensure end-to-end connectivity.

Incorrect Options:

TCP ports 3784 and 4784 (C and D):BFD does not use TCP.

Comprehensive and Detailed in-depth Step-by-Step Explanation:

AnArea Border Router (ABR)is an OSPF router that connects multiple areas, including the backbone area (Area 0). It plays a critical role in summarizing and propagating routing information between areas. The types of LSAs that an ABR can generate include:

Network Summary LSA (Type 3):

ABRs generate Type 3 LSAs to summarize and propagate routes from one area into another.

For example, an ABR generates a Type 3 LSA to inform other areas about the networks in the area it is connected to.

ASBR Summary LSA (Type 4):

If an ASBR exists in one of the OSPF areas connected to the ABR, the ABR generates Type 4 LSAs.

These LSAs provide information about how to reach the ASBR.

NSSA LSA (Type 7):

If the ABR is connected to a Not-So-Stubby Area (NSSA), it can generate Type 7 LSAs.

These LSAs are used to describe external routes imported into the NSSA.

AS External LSA (Type 5):

These LSAs are not typically generated by an ABR unless the ABR is also functioning as an ASBR. Type 5 LSAs are used to describe external routes imported into OSPF from other autonomous systems.

Therefore,NSSA LSA (A),Network Summary LSA (C), andASBR Summary LSA (D)are valid answers.AS External LSA (B)would only be correct if the ABR were also functioning as an ASBR, but that is not explicitly stated in the question.

TheOriginattribute in thedisplay bgp routing-tableoutput is marked asi, indicating that the route was injected into the BGP routing table using thenetworkcommand. The other options are incorrect because the AS path is not displayed, the MED is0, and the route is marked as the best (>), meaning it is the optimal route ​.

 Additional Port Roles in MSTP

Master Port: Indicates the port on the shortest path to the root bridge in a region.

Regional Edge Port: Identifies a port at the boundary of the MST region.

Backup and edge ports exist in RSTP and are not newly introduced by MSTP.

 HCIP-Datacom-Core Reference

MSTP port roles are elaborated in the MSTP configuration sections​​.

Comprehensive and Detailed in-depth Step-by-Step Explanation:

In an Intermediate System to Intermediate System (IS-IS) network, aDesignated Intermediate System (DIS)is elected on broadcast networks to perform the following functions:

Represent the broadcast network as a pseudonode.

Generate and update the Link State Protocol Data Units (LSPs) for the pseudonode.

The DIS is elected based on theDIS priorityvalue, which is configured on IS-IS interfaces. If two routers have the same priority, the router with the higher MAC address becomes the DIS.

Thedefault DIS priorityfor IS-IS interfaces is64, which can be modified depending on the network requirements.

Option A (200):Incorrect. This is not the default value.

Option B (64):Correct. This is the default DIS priority value.

Option C (1):Incorrect. This is not the default value.

Option D (100):Incorrect. This is not the default value.

Comprehensive and Detailed In-Depth Explanation:

IP Multicast vs. Broadcast:

A. TRUE→ Unlikebroadcast, which sends data toall hostsin a subnet,multicast only sends data to interested receivers,preventing flooding.

B. TRUE→Multicast optimizes bandwidth usageby sending asingle copy of data, which is thenreplicated at network routers only when necessary.

IP Multicast vs. Unicast:

C. FALSE→Multicast does not improve security; it may expose data to unintended receivers ifnot properly controlled.

D. FALSE→Multicast reduces the load on the sourcebecause asingle data stream serves multiple receiversinstead of sendingindividual unicast streams.

????Reference:Huawei HCIA-Datacom Study Guide, IP Multicast Principles and Benefits.

 ACL in Routing Policies

ACLs are frequently used in routing policies to match specific routes based on criteria such as source IP, destination IP, and more. This allows ACLs to influence route redistribution, filtering, and forwarding decisions.

 HCIP-Datacom-Core Reference

ACL applications in routing policies are discussed in the routing policy chapters​​.

 IS-IS Interface Types

IS-IS interfaces are categorized based on physical link characteristics:

Point-to-Point (P2P): Direct connections between two routers.

Broadcast: Shared medium networks where multiple routers communicate.

 Incorrect Options

C. P2MP and D. NBMA are not standard interface classifications in IS-IS.

 HCIP-Datacom-Core Reference

IS-IS physical link classifications are elaborated in IS-IS link configuration sections​​.

The monitoring plane's primary role is environmental monitoring, ensuring the stability of the system. Functions like voltage monitoring, temperature tracking, fan speed control, and power management are standard. These are independent of the forwarding or control planes and critical for maintaining device health in network operations ​.

Routing Entries in PIM

(S, G) entries: Represent the shortest path tree (SPT) from a specific source (S) to a specific multicast group (G). These entries are created after data packets are transmitted directly from the source to the receivers.

(S, G) entries are used in both PIM-DM and PIM-SM modes.

PIM-DM and PIM-SM Modes

InPIM-DM, multicast traffic is initially flooded throughout the network and pruned where no receivers exist. (S, G) entries represent source-specific paths created after the flooding stage.

InPIM-SM, multicast traffic initially flows through a shared tree, but (S, G) entries are created when the network switches to the SPT for more efficient forwarding.

HCIP-Datacom-Core Reference

The functionality and application of (S, G) routing entries are detailed in multicast and PIM configuration chapters​​.

The Link State ID in a Type 3 LSA (Summary LSA) indicates the network or subnet being summarized, not the router ID of an ABR. All other statements accurately describe OSPF functionality, making D the false statement ​.

After Layer 3 roaming, the STA’s traffic is forwarded from the Foreign AP (FAP) to the Foreign AC (FAC), and then to the Home AC (HAC) before reaching the upper-layer network. This ensures that the STA remains on the same subnet without breaking existing sessions ​.

 Understanding BGP Route Summarization:

In Border Gateway Protocol (BGP),route summarizationis a technique used to aggregate multiple specific prefixes into a broader summary prefix. This reduces the size of routing tables and improves routing efficiency.

Summarization helps to hide unnecessary details from other parts of the network while still maintaining connectivity.

HCIP-Datacom-Core Technology Training Material (BGP Route Summarization)​​.

 Suppressing Specific Routes:

When summarizing routes, thesuppress-spec-map keywordis used to suppress specific prefixes so that only the summarized route is advertised.

The suppressed routes are not advertised to BGP peers; instead, only the summary route is propagated.

In OSPF, DR and BDR listen on the multicast address 224.0.0.6, while all OSPF routers (including DR others) listen on 224.0.0.5. DR others establish neighbor relationships with DR and BDR, but they do not listen on 224.0.0.6. This makes Option D incorrect, as only DR and BDR use 224.0.0.6 ​.

BGP routes have a variety ofpath attributesthat describe their characteristics and influence route selection. These attributes include well-known mandatory attributes like AS-PATH and NEXT-HOP, as well as optional attributes like MED and LOCAL_PREF.

In Huawei devices, there is aHuawei-specific attributecalled"preference", which is a local parameter used to influence BGP route selection on the device.

Key Characteristics of "preference":

It is valid only locally on the router.

It is not shared with BGP peers.

It helps the router determine the best route when multiple routes exist for the same prefix.

It appears in the BGP routing table output in lowercase aspreference.

Thus, the correct answer ispreference(entered in lowercase as required).

Comprehensive and Detailed in-depth Step-by-Step Explanation:

To answer this question, we need to understand the roles of OSPF routers:

Area Border Router (ABR):

An ABR is a router that connects multiple OSPF areas. It has at least one interface in the backbone area (Area 0) and one or more interfaces in other OSPF areas.

The ABR performs summarization between areas and propagates routing information between them.

Backup Router (BR):

The term "BR" does not exist in OSPF terminology. Instead, OSPF uses the term "Backup Designated Router (BDR)." The BDR is a backup to the Designated Router (DR) in a specific OSPF broadcast or NBMA (Non-Broadcast Multi-Access) network. The BDR takes over the DR's responsibilities if the DR fails.

Key Clarification:

An ABR is related to the hierarchical structure of OSPF areas and is not tied to the DR/BDR election process.

A router can function as an ABR without ever being a DR or BDR, as these are separate roles.

Therefore, the statement that an ABR must also be a BR isFALSE.

Comprehensive and Detailed In-Depth Explanation:

OSPF-to-BGP route redistributiondoesnot allow modification of MED valuesdirectly using aroute-policyin Huawei devices.

Instead,MED can be set using a BGP attribute policy, not through the import command.

All other options (B, C, D) are correct:

B→ Route-policycan filter imported direct routes.

C→ network commanddoes not modify attributes, only announces existing routes.

D→ peer commandcan set Local Preferencevia route-policy.

????Reference:Huawei HCIA-Datacom Study Guide, BGP Route Policy and Attribute Modification.

Root protection ensures that a designated port does not become a root port by discarding superior BPDUs. However, if superior BPDUs are no longer received, the port can return to its original forwarding state, meaning its role can change. This makes option B incorrect, while the other options correctly describe RSTP behavior ​.

Comprehensive and Detailed Step-by-Step Explanation:

1. Port Priority in RSTP:

RSTP (Rapid Spanning Tree Protocol) elects root and designated ports based on port priority and port ID.

Port priority is a configurable value that helps determine which port becomes the root or designated port when multiple ports are eligible.

The port ID consists of the port priority and port number. When priorities are equal, the port number is used as a tiebreaker.

2. Default Port Priority on Huawei Switches:

On Huawei switches, the default port priority is128.

This value can be adjusted in increments of 16 using the command stp port priority.

3. Analysis of Options:

Option A: 1

Incorrect. This is not the default port priority value.

Option B: 128

Correct. This is the default port priority value on Huawei switches.

Option C: 4096

Incorrect. This is not a valid default port priority value.

Option D: 32768

Incorrect. This is the default bridge priority, not the port priority.

4. Summary:

The default port priority on Huawei switches is128.

Huawei HCIA-Datacom Study Guide, Chapter "RSTP Port Role Election."

IEEE 802.1D-2004: Rapid Spanning Tree Protocol (RSTP).

A is correct– Removing unused accounts helpsminimize the risk surface.

B is false– Email isnot a secure methodfor transferring sensitive information like passwords, even if encrypted.

C is correct–Unique administrator accountshelp with accountability and tracking.

D is false–Long-term password validityreduces security. Passwords should be rotated regularly.

Reference from Huawei HCIP-Datacom-Core Technology Study Guide:

“To secure admin access, avoid account sharing, delete inactive users, and periodically update credentials through secure channels.”

(Chapter: Device Security – Section: Account Management)

Let's break it down step by step based on Huawei's routing protocol behavior:

R1imports thedirect route 10.1.1.0/24intoOSPF.

This route is advertised byR1 to R2 and R3viaOSPF.

BothR2 and R3are runningIS-IS, andbidirectional route redistributionis configured between OSPF and IS-IS.

R2 and R3 bothre-advertisethe OSPF-learned route into IS-IS and then potentiallyre-learnit back from the IS-IS domain, causingredistribution loopsunless properly controlled.

Now, the question focuses onR3’s routing table:

R3 already learns the routedirectly via OSPFfrom R1.

It also learns the same route again viaIS-ISfrom R2 (looped back due to bidirectional redistribution).

Reference from Huawei HCIP-Datacom-Core Technology Study Guide:

“OSPF ASE routes are assigned a default preference of 150. If a route is redistributed from another protocol (like IS-IS) into OSPF, and then re-learned, it is considered an ASE route.”(Chapter: OSPF Advanced Features – Section: Route Redistribution Behavior)

 IP Prefix List Matching Conditions

An IP prefix list matches based on:

Mask: Specifies the subnet mask length.

Action: Specifies whether to permit or deny.

Index: Orders the rules within the prefix list.

Port numbers are not applicable as matching conditions in an IP prefix list.

 HCIP-Datacom-Core Reference

IP prefix list configurations are detailed in the routing policy and route filtering chapters​​.

Comprehensive and Detailed In-Depth Explanation:

Neighbor Discovery Protocol (NDP)replacesARP in IPv6and usesICMPv6 messagesfor:

Router Solicitation (RS)→ Sent by hosts torequest Router Advertisement (RA) messages.

Router Advertisement (RA)→ Sent by routers to announce prefixes and network parameters.

Neighbor Solicitation (NS)→ Used foraddress resolutionandDuplicate Address Detection (DAD).

Neighbor Advertisement (NA)→ Sent in response toNS messages.

Redirect→ Used by routers toredirect hosts to better gateways.

RS is not directly used for address resolution;Neighbor Solicitation (NS) does this, so the answer should beD.

????Reference:Huawei HCIA-Datacom Study Guide, NDP and ICMPv6 Packet Types.

Comprehensive and Detailed Step-by-Step Explanation:

1. Understanding LSA Filtering in OSPF and IS-IS:

The filter-policy command is used in OSPF and IS-IS to control which routing information isimported into the local routing tableoradvertised to other neighbors.

However, itcannot filter LSAs forwarded by neighbors. In OSPF and IS-IS, LSAs are always forwarded unchanged within the area to ensure all routers have a consistent link-state database.

Filtering only affects the routes that are installed into the local routing table or advertised to other areas or neighbors.

2. Why the Statement is False:

LSAs are forwarded without being filtered. This ensures link-state protocols maintain the same network topology view across the network.

The filter-policy import command only controls routes that are installed into the local routing table, not the forwarding of LSAs.

3. Summary:

The statement is FALSE because LSAs cannot be filtered by filter-policy import.

Huawei HCIA-Datacom Study Guide, Chapter "OSPF Route Filtering."

RFC 2328: OSPF Version 2, LSA Propagation Rules.

 Notification Message Purpose

BGP Notification messages are used to report errors or terminate a connection. They do not request peers to resend routing information after routing policies are changed.

Routing updates following policy changes require manual resynchronization, not Notification messages.

 HCIP-Datacom-Core Reference

The purpose and usage of Notification messages are discussed in the BGP operation chapters​​.

 ACL Number Ranges

Basic ACLs: Numbered from 2000 to 2999.

Advanced ACLs: Numbered from 3000 to 3999.

Layer 2 ACLs: Numbered from 5000 to 5999.

User-defined ACLs: Numbered from 4000 to 4999.

 HCIP-Datacom-Core Reference

ACL classifications and their number ranges are covered in the ACL principles and configuration chapters​​.

Comprehensive and Detailed In-Depth Explanation:

Wireless LAN (WLAN) roamingallows mobile devices (STAs) to moveseamlessly between different APswithoutdropping connections.

Types of WLAN Roaming:

Layer 2 roaming→ STAs move between APs in thesame subnetwithout IP address changes.

Layer 3 roaming→ STAs move acrossdifferent subnets, requiringIP address reconfiguration(handled via DHCP or tunneling).

Since roamingprevents service interruptionin large WLAN deployments, the statement istrue.

????Reference:Huawei HCIA-Datacom Study Guide, WLAN Roaming and Seamless Connectivity.

OSPF (Open Shortest Path First) mandates that the backbone area (Area 0) serves as the central area for routing information exchange. To avoid inter-area routing loops, routing information is only exchanged between the backbone area and non-backbone areas, not directly between two non-backbone areas. Consequently, each Area Border Router (ABR) must connect to the backbone area to facilitate this routing exchange ​.

Understanding DIS Election in IS-IS:

On an IS-IS broadcast network, aDesignated Intermediate System (DIS)is elected to create and update pseudonodes for efficient communication.

The election is based on the following criteria:

DIS Priority:The router with the highest priority is elected as the DIS.

Router ID (tie-breaker):If priorities are equal, the router with the highest Router ID is elected.

Analyzing the DIS Priorities and Router IDs:

R1: Priority = 64, Router ID = 1.1.1.1

R2: Priority = 1, Router ID = 2.2.2.2

R3: Priority = 127, Router ID = 3.3.3.3

R4: Priority = 10, Router ID = 4.4.4.4

Among the routers,R3 has the highest DIS priority (127), making it the DIS.

Correct Option:

Option B (R3):Correct, as R3 has the highest priority.

Option A (R1):Incorrect, as its priority is lower (64).

Option C (R4):Incorrect, as its priority is lower (10).

Option D (R2):Incorrect, as its priority is the lowest (1).

Inter-area route calculation in OSPF involves Summary LSAs (Type 3) for summarizing routes across areas and ASBR Summary LSAs (Type 4) for locating ASBRs. While Router LSAs and Network LSAs describe the internal structure of an area, they do not directly participate in inter-area route calculation. Thus, the statement that only Router, Network, and Summary LSAs are involved is false ​.

For first-time configuration of a newly purchased network device, administrators typically use the console port. This direct connection is secure and independent of network configuration, making it suitable for initial setups. Telnet, SNMP, or FTP require prior IP configuration, which is not feasible during the initial setup phase ​.

In the IS-IS protocol, TLV 129 (IPv4 interface address) is used to describe the IP address of an interface. Each TLV type carries specific information, and TLV 129 specifically relates to interface IP addresses ​.

One multicast MAC address maps to 32 multicast IP addresses due to the limited number of bits used in the mapping process. Specifically, the lower 23 bits of the MAC address map to the lower 23 bits of the multicast IP address, while the high 24 bits of the MAC address are fixed as 0x01005E. Thus, Option B is false ​.

Comprehensive and Detailed Step-by-Step Explanation:

1. How Firewalls Match Security Policies:

Firewalls usesecurity policiesto define rules for filtering traffic.

Each policy containsmatching conditions(e.g., source IP, destination IP, protocol, etc.) and anaction(e.g., permit or deny).

Traffic is evaluated against these policies in sequential order, and the first matching policy is applied.

2. Analysis of Each Statement:

Option A: Multiple values can be configured for a single matching condition, and the values are logically ANDed.

Incorrect.

Multiple values for a single matching condition (e.g., multiple source IPs) are logicallyORed, not ANDed. For example, traffic from any of the specified source IPs matches the policy.

Option B: If a security policy contains multiple matching conditions, the relationship between them is AND.

Correct.

When a policy has multiple matching conditions (e.g., source IP AND destination IP AND protocol), all conditions must be met for the policy to match.

Option C: The system has a default security policy named default, where all matching conditions are any and the default action is permit.

Incorrect.

The default security policy typically denies all traffic unless explicitly permitted by user-defined policies.

Option D: When multiple security policy rules are configured, they are sorted in a list by configuration sequence by default. A security policy rule configured earlier is placed higher in the list and has a higher priority.

Correct.

Security policies are processed in sequential order based on their configuration sequence. Policies configured earlier have higher priority and are evaluated first.

3. Summary:

The correct statements areBandD.

OptionA is false. When advertising a route to an IBGP peer, theBGP speaker does not modifythe AS_Path. It simply advertises the routeas-is, preserving the AS_Path learned from EBGP.

Clarification of the options:

Bis correct: When a route is sent to an EBGP peer, the local AS is prepended to the AS_Path.

Cis correct: The AS_Path begins with the local AS when a new route is advertised to an EBGP neighbor.

Dis correct: IBGP doesnotmodify AS_Path when passing routes within the same AS.

Reference from Huawei HCIP-Datacom-Core Technology Study Guide:

“BGP speakers prepend their AS number to the AS_Path only when advertising to EBGP peers. IBGP peers do not alter the AS_Path.”

(Chapter: BGP Path Attributes – Section: AS_Path)

In the provided configuration, IS-IS is enabled onLoopback0but not onLoopback3of R2. As a result, R2 will advertise the route10.0.2.2/32(fromLoopback0) to R1 through IS-IS. However, the route10.0.2.3/32will not be advertised because IS-IS is not enabled on that loopback interface. Theimport-route directcommand does not override this behavior ​.

AI-driven networks focus on maximizing efficiency by minimizing latency to enhance data processing and decision-making speed. The AI era emphasizes leveraging large data volumes and ensuring rapid data center interconnectivity. This makes low latency a critical requirement for AI-ready data center networks, as highlighted in Huawei's AI and data center network optimization materials ​.

Comprehensive and Detailed In-Depth Explanation:

NET (Network Entity Title)is a special form ofNSAP (Network Service Access Point)used inIS-IS routing.

NET consists of three fields:

AFI (Authority and Format Identifier) + IDI (Initial Domain Identifier) + Area Address→ Identifies thearea.

System ID→ Uniquely identifies arouter within an area(similar to an OSPF Router ID).

SEL (NSEL - N-selector)→ Always0in a NET, as IS-IS operates at Layer 3.

SinceSystem IDuniquely identifies ahost/router within an area, the correct answer isA.

????Reference:Huawei HCIA-Datacom Study Guide, IS-IS Addressing and NET Structure.

Comprehensive and Detailed In-Depth Explanation:

IP Prefix listsare used tofilter routesbased onprefix and mask length.

Theoptional parametersinclude:

Index of the prefix list→ Specifiespriority/order(Optional).

Shortest mask length to be matched→ Defines theminimum subnet mask(Optional).

Longest mask length to be matched→ Defines themaximum subnet mask(Optional).

Mask length(D) ismandatorybecause it specifies theexact prefix lengthbeing matched.

????Reference:Huawei HCIA-Datacom Study Guide, Configuring Prefix Lists for Route Filtering.

The prefix list permits the prefix1.1.1.1/24with a mask length greater than or equal to/26and less than or equal to/32. This means only prefixes with the base1.1.1.1and mask lengths between/26and/32will be permitted. Routes like1.1.1.2/16and1.1.1.1/24do not meet the mask length criteria, so they will be denied. Conversely, routes like1.1.1.1/26and1.1.1.1/32satisfy the condition and will be permitted ​.

Comprehensive and Detailed Step-by-Step Explanation:

1. What is L2TP (Layer 2 Tunneling Protocol)?

L2TP is a tunneling protocol used to transport Layer 2 frames over IP networks.

It is commonly used to establish VPNs but does not provide built-in encryption or security for the transmitted data.

2. Why L2TP Requires Additional Security Measures:

Since L2TP does not encrypt traffic, it is vulnerable to eavesdropping and tampering.

To secure L2TP tunnels, it is often paired with IPsec, which provides strong encryption and authentication. The combination of L2TP and IPsec is known asL2TP/IPsec.

3. Why the Statement is TRUE:

The statement accurately describes the limitation of L2TP (lack of encryption) and the need for additional security measures like IPsec.

 MQC and PBR

MQC (Modular QoS Command-Line Interface): Applied to interfaces for classifying and controlling traffic.

PBR (Policy-Based Routing): Used to influence packet forwarding based on policies rather than traditional routing tables.

Both MQC and PBR can be configured on device interfaces to filter incoming/outgoing packets or control their forwarding paths.

 HCIP-Datacom-Core Reference

The use of MQC and PBR on device interfaces is elaborated in the QoS and routing control chapters​​.

Comprehensive and Detailed Step-by-Step Explanation:

Portal Authentication:

Portal authentication uses a web-based mechanism where clients are redirected to a login page.

Communication between the access device and Portal server uses HTTP or HTTPS protocols.

Correct Statements:

Option A:HTTP or HTTPS is used for Portal authentication.

Option D:Portal protocol packets are transmitted overTCPfor reliable communication.

Incorrect Statements:

Option B:Port 2000 is not the default for processing Portal packets.

Option C:The default destination port for communication with the Portal server is not 50100.

Comprehensive and Detailed Step-by-Step Explanation:

1. Single-Hop BFD Session:

A single-hop BFD session is used to detect link failures between directly connected devices.

It is bound to thelocal IP addressand thepeer IP address, and the session relies on these parameters to establish connectivity.

2. Why Modifications Require Deletion:

BFD sessions are tightly bound to their configuration parameters (e.g., local and peer IP addresses).

Modifying these parameters is not supported for an existing session. Instead, you must delete the session and recreate it with the updated parameters.

3. Why the Statement is TRUE:

The statement correctly describes the behavior of BFD sessions, where modifying an existing session is not possible without deleting it first.

Comprehensive and Detailed Step-by-Step Explanation:

1. Overview of PBR (Policy-Based Routing):

Policy-Based Routing (PBR) allows you to override traditional routing decisions by defining user-specific policies.

Interface-Based PBR: Applied to packets arriving at a specific interface and affects traffic being forwarded through the device.

Local PBR: Applied to traffic generated by the local router itself (e.g., locally originated packets such as management traffic).

2. Analysis of Each Statement:

Option A: Interface-based PBR takes effect only for forwarded packets.

Correct (True Statement).

Interface-based PBR applies only to packets arriving at a specific interface and being forwarded through the router. It does not affect locally originated traffic.

Option B: Local PBR takes effect only for locally originated packets.

Correct (True Statement).

Local PBR specifically applies to traffic generated by the router itself, such as pings, SNMP requests, or routing protocol updates.

Option C: Interface-based PBR is configured on an interface and takes effect only for incoming packets on the interface.

Correct (True Statement).

Interface-based PBR is applied directly on the interface using commands like policy-based-route. It only affects traffic entering the specified interface.

Option D: Local PBR is configured in the protocol view.

Incorrect (False Statement).

Local PBR is not configured in the protocol view. It is typically configured using the command local-policy in the system view to handle traffic generated by the router.

3. Summary:

Correct Answer:D (Local PBR is NOT configured in the protocol view).

Huawei HCIA-Datacom Study Guide, Chapter "Policy-Based Routing."

The election of a Designated Router (DR) and Backup Designated Router (BDR) occurs during the OSPF network's initial setup or upon the failure of an existing DR. A new router joining an OSPF network does not automatically preempt the current DR, even if it has the highest priority. DR and BDR elections are not preemptive. The other statements are correct regarding OSPF DR/BDR election processes ​.

Comprehensive and Detailed Step-by-Step Explanation:

Default Next Hop Behavior in BGP:

Locally Originated Routes (A):The next hop is set to the advertising router's interface IP address.

Routes Received from EBGP (B):The next hop is not changed when these routes are advertised to IBGP peers. (This makes Option B false.)

Routes Advertised to EBGP (C):The next hop is set to the interface IP address of the advertising router.

Routes Advertised Between IBGP Peers (D):The next hop is not modified by default.

Incorrect Statement:

Option B is incorrect because the next hop of a non-labeled route received from an EBGP peer is not changed when it is advertised to IBGP peers.

ATotally Stubby Areain OSPF is a special type of stub area where onlyintra-area (Type 1) LSAs,router LSAs, anddefault routes (Type 3 LSA with 0.0.0.0/0)are allowed to be injected. Itblocks inter-area routes (Type 3 LSAs for specific prefixes)andType 5 LSAs (external routes)to reduce the size of the Link-State Database (LSDB) and enhance router performance.

Explanation of the Options:

A. Type 3 specific LSA–❌Correct Answer. These LSAs represent inter-area routes. Totally Stubby Areasdo not allow Type 3 LSAs for specific routes, only for the default route (0.0.0.0/0).

B. Type 1 LSA–✅Allowed. These are Router LSAs generated by routers within the area and are necessary for OSPF to function.

C. Type 3 LSA that describes a default route–✅Allowed. This is the only Type 3 LSA permitted in a Totally Stubby Area. It provides a default route (0.0.0.0/0) to reach external destinations.

D. Type 2 LSA–✅Allowed if there are broadcast or NBMA networks in the area. These describe the network segment in multi-access environments and are generated by the DR.

Official Huawei Reference:

????Huawei HCIP-Datacom-Core Technology Study Guide–

Chapter: OSPF Special Areas

"A totally stub area does not allow inter-area Type 3 LSAs or external Type 5 LSAs to enter. Only a default route is injected in the form of a Type 3 LSA (0.0.0.0/0), which greatly reduces the LSDB size."

????Also refer to:

Huawei VRP Command Guide > OSPF > Configuration Notes > OSPF Special Areas

The Forwarding Information Base (FIB) is derived from the router's routing table and contains the exact forwarding entries used to route packets. It directly guides packet forwarding decisions by matching incoming packets with the correct output interface or next-hop address ​.

Comprehensive and Detailed In-Depth Explanation:

SNMP (Simple Network Management Protocol) v3is a moresecureversion of SNMP, supportingauthentication and encryption.

If theNMS is not receiving SNMPv3 traps, possible causes include:

A. FALSE→ TheSNMP version mismatch does not affect traps; devices can send SNMPv2 traps even when using SNMPv3.

B. TRUE→ If theSNMPv3 password is incorrect, authentication will fail, and traps will not be processed by the NMS.

C. FALSE→ The size of packets sent by theNMSdoes not affectincoming SNMP trapsfrom the router.

D. TRUE→ Thecommunity namemust match on both theNMS and the router, or traps will be ignored.

????Reference:Huawei HCIA-Datacom Study Guide, SNMPv3 Configuration and Authentication.

 BGP Next_Hop Attribute

Unlike IGP, the Next_Hop attribute in BGP does not necessarily have to be the IP address of a peer interface. For example, in multi-hop BGP configurations, the Next_Hop can point to a different router or interface within the network.

 HCIP-Datacom-Core Reference

Details of the Next_Hop attribute and its behavior are outlined in BGP path selection principles​​.

Comprehensive and Detailed Step-by-Step Explanation:

IS-IS Area Division:

IS-IS divides areas byrouters, not by links. A router is assigned to a specific IS-IS area, but it can belong to multiple levels:

Level 1:Maintains the LSDB (Link State Database) for the local area only.

Level 2:Maintains the LSDB for the backbone area and exchanges routes between areas.

Behavior of a Level 1-2 Router:

A router configured as Level 1-2 must maintain two separate LSDBs:

One for intra-area routes (Level 1).

One for inter-area routes (Level 2).

Incorrect Statement:

The statement that an IS-IS router only needs to maintain the LSDB of its area is incorrect because Level 1-2 routers maintain LSDBs for both levels.

 BGP Keepalive Message Behavior

Keepalive messages are used to maintain the Established state of a BGP peer relationship.

The Keepalive timer determines the frequency of these messages and defaults to60 seconds, as per the BGP specification.

 HCIP-Datacom-Core Reference

The Keepalive timer default value is covered in the BGP configuration and operational principles​​.

 IGMP:Manages IPv4 multicast group members and runs on the multicast network's last segment (that is, the network segment where a Layer 3 network device is connected to user hosts).

 PIM:Sends multicast data over the network to the multicast device that is connected to group members that have requested the multicast data, implementing multicast data forwarding based on routes.

 IGMP Snooping:Manages and controls the forwarding of multicast data packets to effectively suppress the flooding of multicast data packets on the Layer 2 network.

 IGMP (Internet Group Management Protocol):

IGMP is used by hosts and adjacent multicast routers to establish and maintain multicast group memberships on a local subnet.

It allows a host to inform a multicast router of its desire to receive multicast traffic for a specific group.

It operates at Layer 3 and runs on the last segment of the network.

HCIP-Datacom-Core Technology Training Material (Multicast Fundamentals)​.

 PIM (Protocol Independent Multicast):

PIM is a routing protocol designed for efficient routing of IP multicast traffic. It determines the paths over which multicast packets should be forwarded.

PIM is "protocol-independent" because it uses the underlying unicast routing table for RPF (Reverse Path Forwarding) checks.

It is responsible for distributing multicast data throughout the network.

 Non-Client Definition in IBGP

In an IBGP setup with a Route Reflector (RR), a non-client is an IBGP peer that is neither the RR itself nor its client.

Non-clients must establish fully meshed IBGP connections with all other non-clients and the RR because IBGP rules prohibit route propagation between non-clients without a direct connection.

 HCIP-Datacom-Core Reference

The behavior of non-clients in an RR topology is clearly outlined in the BGP implementation chapters​​.

In BGP, theAS-Pathattribute is mandatory and must be included in allUPDATEmessages. It records the autonomous systems a route has traversed. Attributes likeLocal-Preference,MED, andPrefvalare optional and may not always be included. TheAS-Pathis crucial for loop prevention and route selection ​.

Comprehensive and Detailed In-Depth Explanation:

InIS-IS, routes are distributed differently based onrouter levels:

Level-1 (L1) routers→ Maintainspecific routes only within their own area.

Level-2 (L2) routers→ Maintainspecific routes for the entire network(inter-area routing).

Level-1-2 (L1/L2) routers→ Storeboth L1 and L2 routesand act asarea border routers.

In the diagram,R2 and R3 are L1/L2 routers, meaning they storespecific routes for both their area and other areas.

R1 is only an L1 router, meaning it only hasintra-area routes, andR7 is an L2-only router, meaning it does not store all specific routes.

Therefore,R2 and R3havespecific routesfor the entire network.

????Reference:Huawei HCIA-Datacom Study Guide, IS-IS Routing Levels and Route Distribution.

The Local-Preference attribute is used within an AS to influence outbound traffic paths. The default value is 100, and it is a well-known discretionary attribute, meaning it is not mandatory and does not travel across AS boundaries ​.

 OSPF Authentication Overview

TheAuth Typefield in the OSPF packet header determines the authentication mode. If theAuth Typeis 1, plaintext authentication is used.

Plaintext authentication involves transmitting the password in an easily readable format, which is less secure compared to MD5.

 HCIP-Datacom-Core Reference

Authentication mechanisms, including plaintext authentication, are detailed in the OSPF security configuration chapter, confirming thatAuth Type = 1corresponds to plaintext​​.

The command output indicates that the OSPF neighbor state isFulland that the neighbor relationship has been established. The statement confirms that the negotiation process during the exchange of DD (Database Description) packets has determined the role of the router, with the local device becoming the slave in the Master-Slave relationship, which is critical for LSA synchronization. The other options do not align with the output or OSPF principles ​

Comprehensive and Detailed Step-by-Step Explanation:

1. What is a Firewall Session?

A firewall session is an entry used to maintain the connection state of a protocol.

When a packet is forwarded, the firewall creates a session for it and tracks subsequent packets for the same connection to ensure efficient forwarding and security enforcement.

2. Analysis of Each Option:

Option A: Subsequent fragment

Incorrect.

A session is created for the initial fragment of a packet. Subsequent fragments are matched to the existing session and do not trigger the creation of a new session.

Option B: ICMP error packet

Incorrect.

ICMP error packets (e.g., Destination Unreachable) are considered exceptions and do not create new sessions.

Option C: GRE (Generic Routing Encapsulation)

Correct.

GRE is a tunneling protocol that encapsulates packets. A firewall creates a session for GRE traffic to track the state of the encapsulated connection.

Option D: TCP (Transmission Control Protocol)

Correct.

TCP is a connection-oriented protocol, and firewalls create sessions for TCP connections to track their state (e.g., SYN, SYN-ACK, FIN).

3. Summary:

The firewall creates sessions forGREandTCPprotocols.

 GMP Snooping Proxy

IGMP snooping proxy allows the switch to substitute for upstream Layer 3 devices and downstream hosts, reducing unnecessary bandwidth consumption by consolidating IGMP messages.

 HCIP-Datacom-Core Reference

The IGMP snooping proxy functionality is described in multicast optimization and IGMP configuration chapters​​

Comprehensive and Detailed Step-by-Step Explanation:

1. Understanding Hybrid Interfaces on a Layer 2 Switch:

Layer 2 switches support different interface types, such asaccess,trunk, andhybridinterfaces.

Atrunk interfaceallows traffic from multiple VLANs to pass through, but frames belonging to the native VLAN are sent untagged, while all other VLAN frames are tagged.

Ahybrid interfaceis more flexible:

It allows traffic from multiple VLANs to pass through, just like a trunk interface.

However, you can configure whether frames for specific VLANs are tagged or untagged as they leave the interface. This feature is useful in certain networking scenarios, such as connecting devices that do not support VLAN tagging.

2. Key Differences Between Trunk and Hybrid Interfaces:

A screenshot of a computer Description automatically generated

3. Why the Statement is TRUE:

The statement accurately describes the functionality of a hybrid interface:

It supports traffic from multiple VLANs.

It allows administrators to configure whether outgoing frames are tagged or untagged for specific VLANs.

4. Summary:

The statement isTRUEbecause hybrid interfaces on a Layer 2 switch support traffic from multiple VLANs and allow flexible tagging configurations.

Comprehensive and Detailed Step-by-Step Explanation:

1. IPv6 and Neighbor Discovery Protocol (NDP):

In IPv4, a host usesARP (Address Resolution Protocol)to map an IP address to a MAC address for communication.

In IPv6,ARP is not used. Instead, IPv6 uses theNeighbor Discovery Protocol (NDP)for address resolution.

2. Why the Statement is FALSE:

IPv6 does not use ARP for resolving link-layer addresses.

IPv6 uses NDP, which operates through ICMPv6 messages to perform the equivalent function.

3. Summary:

The statement is FALSE because IPv6 uses NDP, not ARP, to obtain the link-layer address of the destination host.

OSPF process IDs are locally significant and do not need to match between routers to form neighbor relationships. The other statements correctly describe the behavior of OSPF multi-instances, making Option C false ​.

 Edge Port Behavior

An edge port transitions directly to the Forwarding state but reverts to participating in RSTP calculations if it receives a valid configuration BPDU. Thus, statement C is false.

 HCIP-Datacom-Core Reference

The behavior of edge ports and their transitions are discussed in the RSTP enhancement sections​​.

 LSA Lifetime and Deletion

The LS Age field in the LSA header tracks the age of an LSA. When the LS Age reaches its maximum value (3600 seconds), the LSA is marked for deletion. This ensures old or stale LSAs are removed from the network to maintain accurate routing information.

 HCIP-Datacom-Core Reference

Detailed explanation of LS Age behavior and LSA deletion processes can be found in the OSPF LSDB and LSA sections​​.

For single-hop BFD (Bidirectional Forwarding Detection), the configuration must include the local and remote discriminators to uniquely identify the session endpoints. Additionally, enabling BFD globally is a prerequisite for initiating BFD sessions. Configuring multicast IP addresses isunnecessary for single-hop BFD, as it operates over direct links. Huawei's configuration guidelines specify these requirements to ensure effective deployment and operation of BFD​​.

 Understanding BFD (Bidirectional Forwarding Detection):

BFD is a protocol used to detect link faults quickly between two routers.

Single-hop BFD operates on directly connected links and is commonly used for fast fault detection in routing protocols like OSPF and BGP.

HCIP-Datacom-Core Technology Training Material (BFD Basics and Configuration)​​.

 Mandatory Configurations for Single-Hop BFD:

A. Configure the remote discriminator of a BFD session:The remote discriminator is used to uniquely identify the BFD session at the remote end. This is essential for session establishment.

B. Configure the local discriminator of a BFD session:The local discriminator uniquely identifies the BFD session at the local end. This is required to establish a BFD session.

D. Enable BFD globally:BFD must be enabled globally on the router for the protocol to operate and for session configurations to take effect.

 Optional Configuration:

C. Configure a multicast IP address for BFD:This is not required for single-hop BFD, as it operates over direct links using unicast communication. Multicast is used in other scenarios, like multi-hop BFD.

 Conclusion:The correct configurations for single-hop BFD areA,B, andD.

Comprehensive and Detailed Step-by-Step Explanation:

Definition of the Origin Attribute:

The Origin attribute is a well-known mandatory attribute used to indicate the source of a route. It has three possible values:

i (IGP):The route was injected into BGP using the network command.

e (EGP):The route was learned from an EGP protocol (not commonly used now).

? (Incomplete):The route was redistributed into BGP from another routing protocol.

Analysis of Each Option:

Option A:Correct. When the network command is used, the Origin is set toi (IGP).

Option B:Incorrect. Routes learned from EGP have the Origin attribute set toe (EGP), not? (Incomplete).

Option C:Correct. BGP prefers routes with the Origin attribute in the order:IGP > EGP > Incomplete.

Option D:Correct. The Origin attribute is a well-known mandatory attribute.

The LS age field in OSPF LSAs (Link State Advertisements) is measured in seconds and increments over time in the Link State Database (LSDB). If the LS age reaches the LSRefreshTime (30 minutes), the router that originated the LSA must regenerate it to keep the LSA valid in the network. Options C and B are incorrect since LS age does not decrease, and only the originator regenerates LSAs ​.

Comprehensive and Detailed in-depth Step-by-Step Explanation:

OSPF routers establish neighbor relationships and progress through various states during the adjacency formation process. TheExStart stateis where routers negotiate the master and slaveroles. This negotiation is critical because the master initiates the Data Description (DD) packet exchange process.

Here’s a breakdown of the relevant OSPF states:

ExStart State:

This is the phase where the routers determine which one will act as the master and which will be the slave.

The decision is based on theRouter IDsof the two routers. The router with the higher Router ID becomes the master.

Exchange State:

After the master-slave roles are established, the routers exchange DD packets. These packets contain summaries of the LSAs in their respective LSDBs.

2-way State:

This state indicates that bidirectional communication has been established between the two routers, but it occurs before master-slave negotiation.

Init State:

This is an early state where a router has sent a Hello packet to its neighbor but has not yet received a Hello packet in response.

Key Point:

The negotiation of master and slave roles happens exclusively in theExStart state, makingD. ExStartthe correct answer.