H12-821_V1.0 HCIP-Datacom-Core Technology V1.0 Questions and Answers

Comprehensive and Detailed Step-by-Step Explanation:

IGMPv1 Querier Selection:

In IGMPv1, there is no built-in querier election mechanism. Querier selection depends on the multicast routing protocol (e.g., PIM).

IGMPv2 and IGMPv3 Querier Selection:

In IGMPv2 and IGMPv3, the router interface with the largest IP address in the multicast group is selected as the querier.

Correct Statement:

The statement accurately describes the querier selection mechanisms in IGMP versions.

References:

HCIA-Datacom Study Guide, Chapter: IGMP Querier Mechanism

Huawei Multicast Protocol Comparison

A stateful inspection firewall tracks the state of network connections and only matches the initial packet against its rule set. Subsequent packets in the same connection are matched in the state table. Contrary to this, UDP packets can be inspected by correlating them with connection states, and packets in a single connection are always correlated ​.

In BGP, the AS-Path attribute is mandatory and must be included in all UPDATE messages. It records the autonomous systems a route has traversed. Attributes like Local-Preference, MED, and Prefval are optional and may not always be included. The AS-Path is crucial for loop prevention and route selection ​.

An OSPF AS-external LSA is used to describe routes to networks that are external to the OSPF Autonomous System (AS). This external route information is typically imported into OSPF by an Autonomous System Boundary Router (ASBR).

If the Forwarding Address field in the AS-external LSA is set to 0.0.0.0, this indicates that traffic destined for the external network should be forwarded directly to the ASBR that advertised the external route.

The specific context mentioned here relates to the Not-So-Stubby Area (NSSA), a type of OSPF area designed to handle AS-external routes in a more controlled way. In NSSAs:

Type 7 LSAs are used to describe AS-external routes.

The ASBR within the NSSA converts the Type 7 LSA to a Type 5 LSA before advertising it to the backbone area.

Hence, the correct acronym for the described functionality is NSSA.

References:

Huawei HCIA-Datacom Study Guide, Chapter on "OSPF Area Types".

RFC 3101 – OSPF Not-So-Stubby Area (NSSA) Option.

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.

References:

HCIA-Datacom Study Guide, Chapter: WAN Fundamentals

Huawei Networking Basics

DIS Election in IS-IS:

In IS-IS, the Designated Intermediate System (DIS) is elected on broadcast networks to reduce the number of LSAs exchanged and maintain the LSDB.

The DIS is elected based on priority:

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

If priorities are equal, the System ID is used as a tie-breaker, and the router with the highest System ID becomes the DIS.

ARP spoofing is a Layer 2 attack, as it targets ARP tables in switches or end devices. All other attacks, including IP spoofing, ICMP attacks, and Smurf attacks, are network layer (Layer 3) attacks ​.

The information provided indicates that the configured query interval is 60 seconds, which applies to general queries. Group-specific queries are sent at a shorter interval, usually derived from the maximum response time. Therefore, the statement about a 60-second interval for group-specific queries is false. Other statements regarding maximum response time (10s), IP address, and IGMP version (V2) are correct ​.

 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​​.

IGP routes can be injected into BGP using multiple methods, not just the network command. The import-route command can also be used to redistribute IGP routes into BGP. The network command requires the route to exist in the routing table, while import-route allows direct redistribution ​.

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 latency is 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:

The false statement is B, as Wi-Fi 6 does not achieve zero latency.

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 over TCP for 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.

References:

HCIA-Datacom Study Guide, Chapter: WLAN Portal Authentication

Huawei WLAN Authentication Protocols

Secure access channels include protocols that encrypt the transmitted data to protect against interception or unauthorized access. HTTPS (HyperText Transfer Protocol Secure) ensures data encryption over web communications, while SFTP (Secure File Transfer Protocol) provides secure file transfer by utilizing SSH for data encryption. Telnet and SNMPv2, on the other hand, lack robust encryption and are considered insecure. Huawei security standards highlight the importance of encrypted communication to prevent data leaks ​.

 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​​.

Route summarization in OSPF is restricted to specific routers: Area Border Routers (ABRs) and Autonomous System Boundary Routers (ASBRs). These devices perform summarization to reduce routing table size and minimize advertised routing information between areas or across AS boundaries. Regular routers cannot perform route summarization, making this statement false ​.

The error indicates "Incorrect remote AS," which refers to a mismatch in the autonomous system (AS) numbers during BGP peer configuration. This issue is unrelated to the neighbor address. The neighbor address (10.1.1.5) and timestamp (2010-03-22 12:40:39) provided in the output are correct, and the error type confirms a neighbor relationship issue ​.

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-establish forwarding when needed. State-refresh is not directly involved in SPT establishment but helps maintain the prune state ​.

 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.

Comprehensive and Detailed in-depth Step-by-Step Explanation:The Network Entity Title (NET) is a unique identifier assigned to an IS-IS router. It is derived from the Network Service Access Point (NSAP) address and consists of the following components:

Area Address:

Identifies the area in which the router resides.

Multiple routers in the same IS-IS area must have the same area address.

System ID:

Uniquely identifies the router within the IS-IS area.

The System ID is typically derived from the router's loopback IP address or another unique value.

SEL (Selector Field):

The SEL field is always set to 00 for IS-IS NETs.

The NET is used by IS-IS for route calculation and to identify the router within the IS-IS domain. Therefore, the statement is TRUE.

References:

Huawei HCIA-Datacom Study Guide, Chapter on "IS-IS Addressing".

RFC 1195 – Use of OSI IS-IS for Routing in TCP/IP and Dual Environments.

Comprehensive and Detailed Step-by-Step Explanation:

1. BGP Attributes Overview:

BGP uses attributes to describe the properties of routes. These attributes are classified into the following categories:

Well-Known Mandatory: Attributes that must be recognized and included in every BGP update. Examples: AS_PATH, ORIGIN, NEXT_HOP.

Well-Known Discretionary: Attributes that must be recognized but are not required in every BGP update. Examples: LOCAL_PREF, ATOMIC_AGGREGATE.

Optional Transitive: Attributes that may or may not be recognized, but must be passed along to other BGP peers. Examples: COMMUNITY.

Optional Non-Transitive: Attributes that may or may not be recognized, and are not passed along to other BGP peers. Examples: MED (Multi-Exit Discriminator).

2. Analysis of Each Option:

Option A: Atomic_Aggregate

Correct.

This is a well-known discretionary attribute. It indicates that the advertised route is an aggregate route that summarizes multiple specific routes.

Option B: Local-Preference

Correct.

This is a well-known discretionary attribute. It is used within an AS to prioritize routes, with higher values being preferred.

Option C: Community

Incorrect.

The COMMUNITY attribute is an optional transitive attribute. It is used to tag routes with specific labels to apply routing policies.

Option D: MED (Multi-Exit Discriminator)

Incorrect.

The MED attribute is an optional non-transitive attribute. It is used to influence the choice of the preferred path when there are multiple entry points into an AS.

3. Summary:

Well-Known Discretionary Attributes: Atomic_Aggregate and Local-Preference.

In the PIM protocol, Register Stop and Graft messages are sent with unicast destination addresses, typically to specific neighbors or RP (Rendezvous Point) routers. Other messages like Bootstrap and Assert use multicast addresses for broader dissemination across the network ​.

Comprehensive and Detailed Step-by-Step Explanation:

1. Overview of IP Multicast:

IP multicast is a method of delivering data from one source to multiple destinations simultaneously.

Unlike unicast (one-to-one communication) or broadcast (one-to-all communication), multicast is one-to-many, allowing data to be sent only to subscribers (multicast group members).

This significantly conserves bandwidth and reduces the load on the network because the source only sends a single stream of data, which is replicated by multicast routers as needed.

2. Use Cases for IP Multicast:

IP multicast is widely used in network services that involve real-time or large-scale data delivery, such as:

IPTV (Internet Protocol Television): Broadcasting live TV streams.

Real-Time Data Transmission: Delivering stock market data, sensor updates, etc.

Multimedia Conferencing: Supporting group calls, webinars, and online meetings.

3. Why the Statement is TRUE:

IP multicast reduces unnecessary traffic and maximizes efficiency, making it ideal for these types of network services.

When two BGP peers negotiate the Hold Time, the shorter value between the two configured Hold Time values is selected. This ensures compatibility and maintains the stability of the BGP session ​.

High-availability Stateful Backup (HSB) ensures synchronization between active and standby devices. If the HSB channel fails to establish, the following causes are possible:

TCP channel not established: The HSB channel relies on a TCP connection. If the TCP session cannot be established, the backup process cannot start.

Mismatched retransmission settings: If the retransmission count and interval for HSB service packets are inconsistent between the two devices, the synchronization process fails.

Incorrect source and destination configurations: If the source IP address and port number on one device do not match the destination IP address and port number on the other, the channel cannot be established.

Option C is incorrect because the priority of the two ACs affects active/standby roles but does not directly impact HSB channel establishment ​.

OSPF routers refresh and flood LSAs in the Link-State Database (LSDB) every 30 minutes by default to maintain topology consistency. OSPF does not rely on TCP; it uses its own acknowledgment mechanism. It also uses the Dijkstra algorithm, not Bellman-Ford. The flooding interval for LSU packets is shorter, typically 5 seconds ​.

Network Types and Corresponding Link Layer Protocols

Broadcast: Ethernet

Point-to-Point (P2P): PPP, HDLC

Point-to-Multipoint (P2MP): PPP

Non-Broadcast Multi-Access (NBMA): Frame Relay

 OSPF Network Types:OSPF classifies networks based on link layer protocols into the following types:

Broadcast: This type assumes that all routers on the network can communicate directly with one another using multicast or broadcast frames. Ethernet networks are typical examples.

Point-to-Point (P2P): This type is used for links that connect two routers directly. Common protocols include PPP (Point-to-Point Protocol) and HDLC.

Point-to-Multipoint (P2MP): This type simulates multiple point-to-point connections over a single physical network, often used in WAN scenarios where PPP is employed.

Non-Broadcast Multi-Access (NBMA): These networks connect multiple devices but lack native broadcast capability, such as Frame Relay.

When configuring VRRP, the virtual router priority and virtual IP address are mandatory because they define the VRRP instance and its role within the group. Preemption mode and preemption delay are optional configurations that influence how routers take over the master role when priorities change. These are not mandatory for the VRRP protocol to function ​.

Explanation of IS-IS Packet Types and Synchronization Process:

In the given scenario, R2 requests LSPs from R1 to synchronize its Link State Database (LSDB). The following IS-IS packet types are involved in this synchronization process:

1. P2P IIH (Point-to-Point IS-IS Hello):

Purpose: Establishes and maintains IS-IS neighbor relationships.

Step: This packet is exchanged initially to detect and maintain the adjacency between R1 and R2.

2. PSNP (Partial Sequence Number PDU):

Purpose: Requests missing or outdated LSPs (Link State PDUs) from a neighbor to synchronize the LSDB.

Step: In this case, R2 sends a PSNP to R1 to request the missing or outdated LSP.

3. LSP (Link State PDU):

Purpose: Contains routing information and is used to update the LSDB.

Step: R1 sends the requested LSPs to R2 for synchronization.

4. CSNP (Complete Sequence Number PDU):

Purpose: Lists all LSPs in the sender's LSDB to help neighbors verify and request missing LSPs.

Step: R1 sends a CSNP during retransmission timeout to notify R2 of its LSPs.

Comprehensive and Detailed Step-by-Step Explanation:

OSPF State Machine:

OSPF adjacency progresses through several states: Down > Init > 2-Way > ExStart > Exchange > Loading > Full.

The 2-Way state indicates that routers have exchanged Hello packets but are not forming full adjacencies.

Possible Causes for Staying in the 2-Way State:

Hello Time Values Are Different (A): Mismatched Hello/Dead intervals prevent adjacency establishment.

Area IDs Are Different (B): OSPF routers must belong to the same area to establish adjacency.

Router IDs Conflict (C): While Router ID conflicts cause other issues, they do not result in the 2-Way state.

N-bit and E-bit Are the Same (D): Matching N-bit/E-bit values are normal and do not cause problems.

References:

HCIA-Datacom Study Guide, Chapter: OSPF Adjacency Establishment

Huawei OSPF Neighbor State Analysis

In a stateful inspection firewall, if the status detection mechanism is enabled, it tracks and validates the state of connections using the session table. If there is no session table and a SYN+ACK packet reaches the firewall, it checks the security policy. If the policy explicitly permits the packet, it will pass through the firewall, but no session table will be created without the initial SYN packet. The other options are either incorrect or misrepresent the behavior of stateful inspection ​.

 OSPF LSA Flooding Mechanism

If a router receives an LSA identical to one already in its LSDB, it does not flood the LSA again unless the LSA has changed (i.e., the sequence number or content has been updated).

OSPF ensures efficient use of bandwidth by avoiding redundant flooding of unchanged LSAs.

 HCIP-Datacom-Core Reference

The OSPF LSDB synchronization process explains that unchanged LSAs are not reflooded, ensuring stability and resource optimization​​.

According to BGP route selection rules, a higher Local_Pref value indicates a more preferred route. This rule is used to influence traffic flow within an autonomous system (AS), giving preference to routes with a higher Local_Pref for outgoing traffic ​.

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 the bestroute med-none-as-maximum command is configured to treat it as 4294967295 ​.

Comprehensive and Detailed Step-by-Step Explanation:

Overview of IGMP Versions:

IGMPv1: The simplest version, supports basic group membership management using Report messages but lacks Leave messages.

IGMPv2: Adds features like Leave messages and Group-Specific Queries.

IGMPv3: Supports specifying multicast sources for Source-Specific Multicast (SSM).

Feature Supported by All Versions:

Report messages are fundamental to IGMP functionality and are supported in all three versions.

Features Not Supported by All Versions:

Group-Specific Queries (A): Supported in IGMPv2 and IGMPv3.

Leave Messages (B): Introduced in IGMPv2.

Specifying Multicast Sources (D): Introduced in IGMPv3.

References:

HCIA-Datacom Study Guide, Chapter: IGMP Overview

Huawei Multicast Protocol Details

Comprehensive and Detailed Step-by-Step Explanation:

VRRP Virtual MAC Address Format:

The VRRP virtual MAC address is generated using the format:0000-5e00-01XX, where XX represents the VRID in hexadecimal.

Calculation:

VRID = 1 → Hexadecimal = 01.

Virtual MAC = 0000-5e00-0101.

Correct Option:

C (0000-5e00-0101).

References:

HCIA-Datacom Study Guide, Chapter: VRRP MAC Address Format

Huawei VRRP Configuration Guidelines

Let me continue with the next set of questions!

 Export Routing Policy Changes

When an export routing policy is modified, BGP does not automatically resend affected routes. Manual intervention, such as a clear ip bgp command, is required to resend Update messages reflecting the new policy.

 Incorrect Options

B. IGP routes can also be advertised into BGP using redistribution, not just the network command.

C. A router can be configured with multiple BGP processes using different AS numbers (multi-instance BGP).

D. Open messages carry additional parameters such as AS number, Hold Time, and Router ID, not just the header.

 HCIP-Datacom-Core Reference

BGP policy and update behavior are detailed in the route control and redistribution chapters​​.

The asbr-summary command is executed in the global OSPF view to summarize external routes. The abr-summary command is executed in the OSPF area view to summarize routes between areas. By default, the advertise parameter is enabled unless explicitly overridden by the not-advertise option ​.

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 ​.

The security policy specifies that traffic originating from 12.1.1.2 and destined for the untrust zone is permitted. Since the source address of the packet (12.1.1.1) does not match this rule, the packet matches the default implicit deny rule. However, rule 1 does not deny all other traffic explicitly, so the packet is forwarded based on further configurations ​.

The operator between if-match clauses under a node is AND, meaning all conditions must be satisfied. However, the operator between nodes is OR, meaning a route matching any node will pass the route-policy ​.

IGMPv3 builds on IGMPv1 and IGMPv2 by supporting all previous query types, including General Query and Group-Specific Query, while introducing Source/Group-Specific Query. This enhancement allows finer control over multicast group membership ​.

An IP prefix filter is designed to match both the IP address and its prefix length, making it suitable for filtering routing information rather than data packets. Options A and D are incorrect because IP prefix filters do not work directly on data packets, and they can match both prefix numbers and lengths ​.

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 ​.

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:

1. What is NETCONF?

NETCONF (Network Configuration Protocol) is an XML-based protocol used for network device configuration and management.

It enables reading, modifying, deleting, and restoring configurations programmatically.

2. Supported Operations:

Option A: Modifying configurations

Correct.

NETCONF allows you to modify existing configurations on network devices.

Option B: Deleting configurations

Correct.

Configurations can be deleted using NETCONF operations.

Option C: Restoring configurations

Correct.

NETCONF can restore configurations by applying previously saved configuration data.

Option D: Backing up configurations

Correct.

NETCONF can retrieve and save the current configuration as a backup.

3. Summary:

NETCONF supports all listed operations: modifying, deleting, restoring, and backing up configurations.

Router LSAs (Type 1) and Network LSAs (Type 2) are advertised only within a single OSPF area, as they describe the topology within the area. In contrast, Summary LSAs (Type 3) and AS External LSAs (Type 5) are used for inter-area and external routing, respectively ​.

Comprehensive and Detailed Step-by-Step Explanation:

1. Understanding the Prefix List Configuration:

The command ip ip-prefix test index 10 permit 10.0.0.0 8 less-equal 32 defines the following:

The prefix base is 10.0.0.0 with a mask length of 8 bits.

The less-equal 32 condition allows routes with mask lengths ranging from 8 to 32 bits to match.

2. Analysis of Each Route:

Option A: 10.1.1.1/32

Correct.

The prefix 10.1.1.1/32 falls within the 10.0.0.0/8 network range and has a mask length of 32 bits, which satisfies the less-equal 32 condition.

Option B: 10.1.1.0/6

Incorrect.

The prefix 10.1.1.0/6 has a mask length of 6 bits, which is shorter than the base prefix length of 8. It does not satisfy the condition.

Option C: 10.1.1.0/24

Correct.

The prefix 10.1.1.0/24 falls within the 10.0.0.0/8 network range and has a mask length of 24 bits, which satisfies the less-equal 32 condition.

Option D: 10.0.0.0/16

Correct.

The prefix 10.0.0.0/16 falls within the 10.0.0.0/8 network range and has a mask length of 16 bits, which satisfies the less-equal 32 condition.

3. Summary:

The prefixes that match the configuration are 10.1.1.1/32, 10.1.1.0/24, and 10.0.0.0/16.

Comprehensive and Detailed Step-by-Step Explanation:

HSB (Hot Standby Backup) Service:

HSB is used on WLAN controllers to back up critical information in real time to a backup device, ensuring service continuity in case of failures.

Backed-Up Information:

CAPWAP Tunnel Information (A): Essential for maintaining connections between APs and controllers.

AP Entries (C): Information about connected APs is backed up.

User Data Information (D): Includes client authentication and session details.

Incorrect Option:

DHCP Address Information (B): Not part of HSB's responsibilities, as DHCP is handled separately.

References:

HCIA-Datacom Study Guide, Chapter: WLAN Redundancy with HSB

Huawei HSB Configuration Guide

Comprehensive and Detailed Step-by-Step Explanation:

Definition of Link Aggregation:

Link aggregation combines multiple physical links into a single logical link to improve bandwidth and reliability.

Advantages of Link Aggregation:

Load Balancing (A): Traffic is distributed across all aggregated links to improve performance.

Improved Reliability (B): If one link fails, traffic is rerouted through other links.

Increased Link Bandwidth (C): Bandwidth is effectively the sum of all aggregated links.

Incorrect Option:

Route Backup (D): Route backup is a feature of routing protocols, not link aggregation.

References:

HCIA-Datacom Study Guide, Chapter: Link Aggregation Fundamentals

Huawei Link Aggregation Configuration

Based on the MSTP configuration shown, the role of the switch in MSTI 1 cannot be determined without additional details about the topology or priority values of other switches in the instance. The role could be a root switch, secondary root, or non-root, depending on these factors ​.

Configuration Analysis:

On R2, the following configuration has been applied:acl 200rule deny source 10.1.0.0 0.0.3.0rule permit#ospf 1filter-policy 2000 import

On R2, the following configuration has been applied:acl 200rule deny source 10.1.0.0 0.0.3.0rule permit#ospf 1filter-policy 2000 import

On R2, the following configuration has been applied:acl 200rule deny source 10.1.0.0 0.0.3.0rule permit#ospf 1filter-policy 2000 import

On R2, the following configuration has been applied:acl 200rule deny source 10.1.0.0 0.0.3.0rule permit#ospf 1filter-policy 2000 import

On R2, the following configuration has been applied:acl 200rule deny source 10.1.0.0 0.0.3.0rule permit#ospf 1filter-policy 2000 import

On R2, the following configuration has been applied:acl 200rule deny source 10.1.0.0 0.0.3.0rule permit#ospf 1filter-policy 2000 import

On R2, the following configuration has been applied:acl 200rule deny source 10.1.0.0 0.0.3.0rule permit#ospf 1filter-policy 2000 import

On R2, the following configuration has been applied:acl 200rule deny source 10.1.0.0 0.0.3.0rule permit#ospf 1filter-policy 2000 import

This configuration uses ACL 200 to filter routes during import into the OSPF routing table on R2.

Rule deny source 10.1.0.0 0.0.3.0: Blocks routes in the range 10.1.0.0/24 to 10.1.3.0/24 (inclusive).

Rule permit: Allows all other routes to be imported.

Impact of ACL 200 on Route Import:

10.1.0.0/24 to 10.1.3.0/24: These subnets are explicitly denied by ACL 200 and will not appear in R2's routing table.

10.1.4.0/24 and beyond: These subnets are permitted by the rule permit statement and will be imported into R2's routing table.

Routing Table Entries on R2:

Option A (10.1.4.0/24): Exists in R2's routing table because it is permitted.

Option B (10.1.3.0/24): Does not exist because it is denied by ACL 200.

Option C (10.1.2.0/24): Does not exist because it is denied by ACL 200.

Option D (10.1.1.0/24): Does not exist because it is denied by ACL 200.

A (10.1.4.0/24)

Correct Options:References:

HCIA-Datacom Study Guide, Chapter: OSPF Route Filtering

Huawei ACL Configuration for Route Policies

Intra-area route calculation in OSPF involves only Router LSAs (Type 1) and Network LSAs (Type 2). Summary LSAs (Type 3) are used for inter-area routes and do not participate in intra-area route calculation. Therefore, the statement is false ​.

Comprehensive and Detailed in-depth Step-by-Step Explanation:In an Intermediate System to Intermediate System (IS-IS) network, a Designated 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 the DIS priority value, which is configured on IS-IS interfaces. If two routers have the same priority, the router with the higher MAC address becomes the DIS.

The default DIS priority for IS-IS interfaces is 64, 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.

References:

Huawei HCIA-Datacom Study Guide, Chapter on "IS-IS Basics".

RFC 1195 – Use of OSI IS-IS for Routing in TCP/IP and Dual Environments.

In an OSPF broadcast or NBMA network with at least two routers, one router must act as the DR (Designated Router), and another as the BDR (Backup Designated Router) to ensure efficient communication and reduce the number of adjacencies. This is a requirement for OSPF operation in such network types ​.

Comprehensive and Detailed Step-by-Step Explanation:

IPv4 Address Classes:

Class D: Reserved for multicast and defined by the first four bits as 1110.

Address range: 224.0.0.0 to 239.255.255.255.

Structure:

Class D does not include a network/host division, as it is designed for group communication rather than device identification.

References:

HCIA-Datacom Study Guide, Chapter: IPv4 Address Classes

Huawei Multicast Configuration Guidelines

Let me continue with the next set of questions!

A stateful inspection firewall tracks the state of active connections. If a packet matches an existing session in the firewall's state table, it is allowed to pass. The diagram indicates that the TCP packet matches the session state, so the firewall forwards it ​.

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 ​.

IPv4 supports three main transmission modes:

Unicast: One-to-one communication.

Broadcast: One-to-all communication within a network.

Multicast: One-to-many communication to a group of interested receivers.Anycast is not a native IPv4 mode but is introduced in IPv6 ​.

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 ​.

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.

References:

HCIA-Datacom Study Guide, Chapter: BGP Next Hop Behavior

Huawei BGP Routing Principles

GRE (Generic Routing Encapsulation) is not a Layer 2 VPN technology. Instead, it is a Layer 3 tunneling protocol used to encapsulate a wide variety of network layer protocols inside point-to-point connections. GRE is commonly used for creating VPN tunnels across IP networks, allowing for the transport of various types of payloads. This misunderstanding about GRE being a Layer 2 technology contradicts its definition and typical application ​.

 ACL Modification

Named ACLs can be modified after their creation. Unlike numbered ACLs, named ACLs provide greater flexibility for editing individual rules without deleting the entire ACL.

Therefore, the statement is incorrect.

 HCIP-Datacom-Core Reference

The flexibility and editability of named ACLs are discussed in the ACL configuration sections​​.

1. Understanding Prefix List Configuration:

The command ip ip-prefix huawei index 10 permit 10.1.1.0 24 greater-equal 26 defines a prefix filter:

The base prefix is 10.1.1.0/24.

The greater-equal 26 condition specifies that the mask length of matching prefixes must be at least 26 bits.

If the less-equal parameter is not explicitly defined, the default value is 32, meaning the longest possible mask length for IPv4.

2. Explanation of Values:

greater-equal-value: Specifies the minimum mask length. In this case, the value is 26.

less-equal-value: Specifies the maximum mask length. Since it is not explicitly configured, the default value is 32.

3. Summary:

greater-equal-value = 26

less-equal-value = 32

Comprehensive and Detailed Step-by-Step Explanation:

1. Understanding the AS-Path Filter:

The as-path-filter command is used in BGP to filter routes based on the AS_PATH attribute.

In this configuration:

The filter si is defined with the regular expression _65500$.

The _65500$ expression specifies that the AS_PATH must end with 65500, meaning that the route's last hop must have passed through AS 65500.

2. Option Analysis:

Option A: It accepts only the routes whose AS_Path contains AS 65500.

Incorrect.

The _65500$ filter specifically matches routes where AS 65500 is the last AS in the AS_PATH. A route may contain AS 65500 somewhere in the middle of the AS_PATH but will not match this filter unless it is the last AS.

Option B: It accepts only the routes originated from AS 65500.

Incorrect.

Routes that originate from AS 65500 have an AS_PATH that starts with 65500. However, the filter _65500$ only matches routes where AS 65500 is the last AS, not the first AS.

Option C: It accepts only the routes that last pass through AS 65500.

Correct.

The _65500$ filter ensures that the AS_PATH ends with 65500. This means that the route must have last passed through AS 65500 before being received by the local BGP router.

Option D: It accepts only the routes forwarded by AS 65500.

Incorrect.

While AS 65500 may forward the route, this is not what the filter _65500$ specifically checks for. It only ensures that AS 65500 is the last AS in the AS_PATH.

3. Summary:

The as-path-filter with _65500$ accepts only the routes where AS 65500 is the last AS in the AS_PATH.

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 ​.

Policy-Based Routing (PBR) on interfaces is used to forward traffic based on specific policies rather than the routing table. However, PBR is not suitable for modifying the next-hop of locally originated traffic. Other scenarios listed are typical use cases for interface PBR ​.

Multi-channel protocols such as H.323 and FTP use separate control and data channels. H.323 uses different channels for call signaling and media streaming, while FTP uses a control channel for commands and a data channel for file transfers. Telnet and SMTP are single-channel protocols ​.

Comprehensive and Detailed Step-by-Step Explanation:

Multi-Channel Protocols:

Multi-channel protocols use separate channels for control and data communication, requiring application-specific packet filtering (ASPF) to track sessions.

Examples:

FTP (A): Uses separate control and data channels.

SIP (B): Uses multiple ports for signaling and media.

H.323 (D): A VoIP protocol using multiple channels.

Single-Channel Protocol:

SMTP (C): A single-channel protocol for email communication, which does not require ASPF.

References:

HCIA-Datacom Study Guide, Chapter: Firewall ASPF Configuration

Huawei Multi-Channel Protocol Handling

In Layer 3 roaming scenarios, STAs (stations) remain on different subnets before and after roaming. To ensure that user traffic reaches the original subnet, it must be tunneled back over a CAPWAP tunnel. This technique prevents disruptions in communication and enables seamless roaming. Huawei’s Layer 3 roaming design guidelines emphasize the use of CAPWAP tunnels for user traffic forwarding ​.

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.

References:

HCIA-Datacom Study Guide, Chapter: BGP Session Establishment

Huawei BGP Timers and Session Management

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 is 128.

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 is 128.

 BGP Route Flapping and Mitigation

While route flapping is a concern in large-scale networks, BGP employs mechanisms such as Route Dampening to mitigate its impact. Route dampening suppresses frequently flapping routes for a period of time to reduce resource consumption and network instability.

Therefore, it is incorrect to state that the issue cannot be resolved in BGP.

 HCIP-Datacom-Core Reference

The mechanism of route dampening is detailed in the BGP optimization chapters​​.

 pat

 trust

 12.1.1.0

 inner

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 ​.

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 for GRE and TCP protocols.

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 ​.

Comprehensive and Detailed Step-by-Step Explanation:

1. Overview of AS_Path Attribute Modification:

The apply as-path command in a route-policy is used to modify the AS_Path attribute of routes. This is often required to influence the selection of routes or to adjust routing policies for incoming or outgoing BGP updates.

2. Parameters of the apply as-path Command:

Option A: Delete

Correct.

The delete parameter removes specific AS numbers from the AS_Path attribute. This is used to simplify or manipulate the AS_Path for specific routing policies.

Option B: Additive

Correct.

The additive parameter appends an AS number to the existing AS_Path attribute, instead of overwriting it. This is useful when you want to prepend AS numbers to influence route selection without removing the original AS_Path.

Option C: Copy

Incorrect.

The copy parameter is not supported in the apply as-path command for modifying AS_Path attributes.

Option D: Overwrite

Correct.

The overwrite parameter replaces the existing AS_Path with a new one. This provides complete control over the AS_Path attribute but removes the original AS_Path entirely.

3. Summary:

The valid parameters for the apply as-path command are delete, additive, and overwrite.

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 ​.