Huawei H12-891 Exam Prep
HCIE-Datacom V1.0 (Page 28 )

• Employees can use approved devices from remote locations or worldwide offices.
• Users do not need to carry or insert extra hardware.
• It helps prevent account takeovers from unknown devices.

• Geotagging: Restricts access based on location, which could interfere with remote work and travel.
• Smart cards: Require additional physical equipment and card readers.
• Time-based logins: Limit access according to time but do not strongly bind access to an authorized user device.

• VM CPU, memory, disk, and network usage
• Storage transactions and latency
• App Service response time
• Database DTU or CPU utilization

• Azure Traffic Analytics analyzes network traffic flows and security patterns; it is not the general infrastructure metrics tool.
• Azure Activity Log records subscription-level control-plane operations, such as resource creation, deletion, or configuration changes.
• Azure Advisor provides recommendations about cost, security, reliability, performance, and operational excellence, but it is not the primary tool for investigating live metrics.

1. Product + ProductSubCategory: Inner join

1. Result + ProductCategory: Left outer join

• Due Date
• Order Date
• Delivery Date

DAX 
Order Date = 'Due Date' 
Delivery Date = 'Due Date'

• Due Date[Date] ? Sales[Due Date]
• Order Date[Date] ? Sales[Order Date]
• Delivery Date[Date] ? Sales[Delivery Date]

1. Modify the database subnet NACL inbound rules to allow traffic from the new web subnet’s CIDR block on the MySQL port (3306).
2. Modify the database subnet NACL outbound rules to allow return traffic to the new web subnet’s CIDR block on the required ephemeral port range.

• B. Data loss prevention (DLP): Helps prevent sensitive data from being copied, emailed, or exfiltrated. It is not the primary control for protecting a stolen laptop’s stored data.
• C. Operating system hardening: Reduces vulnerabilities by disabling unnecessary services and applying secure settings, but it does not necessarily protect the files if the disk is accessed directly.
• D. Boot security: Helps ensure the device starts only through trusted software or approved processes. It supports platform integrity but does not itself encrypt stored files.

• A — Reports: Reports are informational and don’t enforce access during an SSO transaction.
• B — Apex trigger and Permission Sets: A trigger could update permissions when a Case changes, but this creates synchronization and timing issues. It also changes Salesforce permissions rather than making a direct, real-time decision for the external system.
• C — Custom SAML JIT Provisioning: JIT provisioning is primarily for creating or updating users at login. It isn’t the appropriate mechanism for dynamically querying business records and deciding whether access should be granted.
• D — Connected App Handler: Designed for custom, programmatic control during connected-app authentication and authorization. Apex can check the user’s current open classified cases and permit or reject the SSO request.

• C — Custom buttons display at the top and bottom of a page: Correct. In Salesforce Classic, buttons can appear in the page’s button areas, including the top and bottom of record pages.
• D — Custom buttons are available for Person Accounts: Correct. Person Accounts use the Account object, so Account custom buttons can be available on Person Account layouts.
• E — Custom buttons can reference an external app: Correct. A URL custom button can launch or navigate to an external application or website.

• A: JavaScript custom buttons are a Salesforce Classic feature and are not supported in Lightning Experience. They do not enhance Lightning Experience.
• B: The User object does not generally support custom buttons in the same way standard business objects do.

• Updating the CRL: Revokes compromised certificates, but does not fix the CA flaw that allowed them to be created.
• Changing passwords: May be necessary if accounts were compromised, but it does not address the certificate-generation vulnerability.
• Implementing SOAR: Improves security automation and response; it does not remediate the underlying PKI weakness.

• Maintain head office control: Transfer pricing generally supports decentralisation rather than direct head-office control.
• Establish centralised decision making: This conflicts with divisional autonomy.
• Develop a top-down culture: Transfer pricing is intended to support empowered divisions and goal congruence, not impose purely top-down management.

• A: My Domain is required for many SSO configurations, but if SSO works, it is unlikely to be the cause of losing the target record.
• B: HTTP-POST is a valid SAML binding and does not inherently prevent redirection.
• D: An incorrect Federation ID generally causes authentication or user-matching failure—not successful login to the home page.

• s3:GetObject for the relevant objects
• s3:ListBucket if listing is required
• Appropriate bucket and object resource permissions

• B: Making the bucket public is insecure and unnecessary.
• C: Prompt engineering cannot override AWS IAM or encryption permissions.
• D: Data sensitivity does not determine whether the role can access it.

• Supervised learning requires labeled examples to learn how to classify customers.
• Reinforcement learning learns through actions, rewards, and penalties, which is not the main task here.
• RLHF uses human feedback to improve model behavior, typically for generative AI, not customer segmentation.

1. Ensure BOMs can include subcomponents ? Configure an entity relationship

1. Report changes made by engineers ? Enable auditing

• Configure entity relationship
• Configure auditing

• Tactics: The attacker’s overall goal, such as gaining persistence or exfiltrating data
• Techniques: The methods used to achieve that goal
• Procedures: The specific implementation or sequence of actions

• IP addresses and hash values: Useful indicators, but they can change quickly.
• Indicators of compromise: TTPs may help identify IOCs, but their main value is describing behavior.
• Tools: Attackers can replace tools or use legitimate administrative utilities.

• Idioma: “Responda em português.”
• Tamanho: “Responda em até três frases.”
• Formato: “Use uma lista com três recomendações.”
• Objetivo: “Recomende produtos com base nas necessidades do cliente.”

• Mudar o tamanho do LLM: pode alterar capacidade e custo, mas não garante idioma ou respostas curtas.
• Aumentar a temperatura: aumenta a criatividade e a aleatoriedade; não controla diretamente o tamanho ou idioma.
• Aumentar o Top K: permite considerar mais tokens prováveis, aumentando a variedade; também não é o mecanismo principal para controlar idioma ou comprimento.

• You can configure different pre-shared keys for different device groups.
• All cameras could use one key.
• All scanners could use another key.
• Each key can be associated with an appropriate role or access policy.

• BIOS language support: Useful for usability, but not whether the PC can operate electrically.
• Supply chain security: Concerns procurement and hardware trust, not deployment across countries.
• Power efficiency: Important for energy usage, but it does not ensure compatibility with local power systems.

1. Start with the 48-bit MAC address.
2. Split it into two 24-bit halves.
3. Insert FF:FE between the halves, creating a 64-bit value.
4. Invert the U/L bit—the seventh bit from the left in the first MAC byte.

text 
MAC:       00:1A:2B:3C:4D:5E 
EUI-64:    02:1A:2B:FF:FE:3C:4D:5E

• FE80 is the prefix commonly used for an IPv6 link-local address, not part of the EUI-64 interface ID.
• The interface ID is not random.
• The MAC address is modified by inserting FF:FE and changing the U/L bit.

• Online payment fraud
• Account takeover
• Fake account creation
• Suspicious transactions

• Laws and regulations
• Litigation holds
• Industry or contractual obligations
• Tax, financial, health, or privacy requirements

• Business strategy and direction: May influence retention, but cannot override legal requirements.
• Storage capacity and longevity: Practical considerations, not the primary driver.
• Business ease and value analysis: May support decisions after compliance obligations are identified.

• Identifying the communication strategy: Usually part of a business continuity or incident response plan.
• Evaluating the risk management plan: Part of risk assessment and risk management activities.
• Establishing backup and recovery procedures: Usually part of disaster recovery planning.
• Developing the incident response plan: Part of incident response planning.

• Scheduling overlapping working hours for critical collaboration
• Assigning independent tasks that can proceed asynchronously
• Adding clear handoffs between offices
• Documenting decisions, questions, and required inputs
• Building appropriate time into the schedule for responses

• Separate accounts/domains create a strong administrative boundary between non-production and production.
• Separate projects provide distinct IAM boundaries, billing, quotas, service accounts, and resources.
• Developers can receive permissions in the development project without automatically gaining access to production.
• Production administrators can be restricted from development resources, supporting separation of duties and least privilege.

• A: Creates excessive project fragmentation without being required by the stated requirement.
• C: Keeps development and production under one account and does not clearly separate administrative duties.
• D: Uses one account and only two projects; it provides some project isolation but weaker organizational separation.

• Owner, Contributor, and Network Contributor provide sufficient management permissions.
• Reader can view Traffic Analytics data but cannot enable or configure it.

• Cloud architecture
• Data architecture
• Platform engineering
• Data engineering
• Provisioning and modernization

• Data protection is associated mainly with security and risk management.
• Data governance belongs to the governance perspective.
• Data science is not an AWS CAF capability.

• A password cracker would normally be identified by behavior such as loading password hashes or attempting dictionary/brute-force attacks.
• The question describes a routine audit, not password recovery.
• Simply encountering a protected file during an audit is characteristic of a misconfigured or insufficiently privileged FIM.

• Tokenization: Replaces the value with a nonsensitive token, often reversible through a secure token vault.
• Hashing: Converts data into a one-way fixed-length value, generally used for integrity checks or password storage.
• Obfuscation: A broad term for making data difficult to understand; it is less precise than masking in this context.

• vSmart controls the overlay control plane. It uses OMP to exchange routing information, distribute policies, and determine how WAN Edge devices reach one another.
• vManage is the centralized management and configuration platform.
• vBond is the orchestrator. It helps devices authenticate, discover controllers, and traverse NAT during onboarding.
• APIC-EM is not the SD-WAN control-plane component described here.

text 
interface GigabitEthernet0/0.10 
 encapsulation dot1Q 3

• .10 is the router’s local subinterface number.
• dot1Q 3 identifies the 802.1Q VLAN tag carried on the trunk.

text 
interface GigabitEthernet0/0.3 
 encapsulation dot1Q 3

text 
interface GigabitEthernet0/0.2 
 encapsulation dot1Q 2

• Documented and formally requested
• Analyzed for security, cost, and operational impact
• Reviewed and approved by the appropriate personnel
• Tested before implementation
• Tracked and reversible if problems occur

• Risk management process: Identifies and evaluates risk, but does not directly authorize design changes.
• Product design process: Applies primarily while creating or developing the product.
• Design review process: May have identified the issues, but the next step for changing an already released design is controlled change management.

sql 
GRANT ALTER ON SCHEMA::schemaA TO User1;

• TRUNCATE TABLE is a DDL operation, not a normal DELETE.
• Having DELETE permission on a table is not sufficient to truncate it.
• The minimum relevant permission is ALTER on the table.
• Granting ALTER on SCHEMA::schemaA allows the user to truncate tables within schemaA.
• It does not grant equivalent permissions on schemaB or schemaC, satisfying least privilege.

• AWS AppSync is designed for serverless applications that need to retrieve and combine data from multiple sources.
• A pipeline resolver can invoke multiple functions or data-source resolvers, including resolvers connected to different DynamoDB tables.
• The application can receive the combined result through one GraphQL request, without requiring custom aggregation logic in the application.
• This is operationally efficient because AppSync manages the API layer and resolver execution.

• Athena Federated Query is intended primarily for analytics and ad hoc querying, not low-latency application data retrieval.
• Querying DynamoDB through Athena can consume DynamoDB read capacity and may affect table performance.
• It also introduces analytical-query overhead and is not the normal choice for a microservice web application.

• Works across SaaS and internal applications: TOTP is widely supported by authentication systems and can be integrated into many applications.
• Device manufacturer agnostic: A hardware token or authenticator application can generate the code without depending on a specific computer or phone manufacturer.
• Offline capability: The code is generated locally using a shared secret and the current time; an internet connection or cellular service is not required.

• Username and password: May work offline but provides weaker authentication and does not meet the intended improvement in security.
• Biometrics: Can depend on device hardware, operating-system support, and enrollment mechanisms.
• SMS verification: Requires cellular connectivity and is vulnerable to threats such as SIM swapping.

• Detect risky sign-ins from unfamiliar or unidentified IP addresses
• Evaluate user or sign-in risk
• Automatically require a password change because of a risky sign-in

• User risk policy: Can require a user to securely change their password when the account may be compromised.
• Sign-in risk policy: Can require MFA or block access based on the risk of a particular sign-in.

• A — Custom Button: A button can launch a flow, typically by passing the flow’s URL and record context.
• D — From a Process: A Process can invoke a flow using an Apex action configured for flow invocation. However, this is automation-triggered, not directly accessed by a user.
• B — Quick Action: In current Salesforce functionality, a Flow Quick Action can launch a screen flow directly from a record page. This makes B a valid modern method.
• C — Visual Workflow Launcher: This is not generally listed as a standard access method in current Salesforce terminology; Salesforce commonly uses the Flow component on Lightning pages instead.

• Application management: Controls which apps can be installed or used; it does not remove existing data after theft.
• Full-disk encryption: Protects data when the device is powered off or locked, but it may not help if the attacker has already unlocked the device.
• Containerization: Separates corporate data from personal data, but the attacker may still access the corporate container using the stolen credentials.

• A — Too infrequent: Formal strategies are often reviewed only every three to five years. This can make the organisation slow to respond to rapid changes in technology, competitors, regulation or customer needs.

• C — Relies on predicting the future: The approach assumes senior managers can make reasonably reliable forecasts and assumptions. In uncertain environments, these assumptions may quickly become invalid.

• E — Can restrict radical innovation: Formal planning tends to favour existing information, established objectives and incremental improvements. This may discourage experimental or highly innovative strategies that emerge from lower levels of the organisation.

• B concerns the difficulty of achieving competitive advantage through core competences when competing with focused specialists. It is not specifically a drawback of the formal top-down planning process.
• D is an activity organisations should undertake—continuous monitoring—not a drawback of the approach itself.

• The S3 bucket as an origin for static content
• The Application Load Balancer (ALB) as an origin for dynamic content
• An Amazon Route 53 alias record pointing the application domain to CloudFront

Why this works

• Static data: CloudFront caches objects from S3 at edge locations, reducing latency for users worldwide.
• Dynamic data: CloudFront forwards requests that require application processing to the ALB. It can also maintain persistent connections and use the AWS global edge network to improve delivery performance.
• One domain: CloudFront behaviors can route different path patterns to different origins—for example, /static/* to S3 and other paths to the ALB.

Why the other options are incorrect

• Global Accelerator is designed primarily for accelerating traffic to applications with endpoints such as ALBs, not for caching S3 content.
• Using separate domains or splitting static and dynamic traffic adds unnecessary complexity.
• CloudFront already provides the required global edge distribution and caching, so combining it with Global Accelerator is unnecessary here.

• Have a definite, clear objective (C): Know exactly what you want to communicate. A clear purpose reduces ambiguity and irrelevant information.
• Plan the communication (E): Decide what to say, who needs the information, the appropriate channel and the best timing.
• Seek feedback (F): Check that the receiver understood the message. This could involve asking for confirmation or inviting questions.

• Ask questions (A): Usually associated with the receiver checking or clarifying information, although a sender may use questions in practice.
• Give feedback (B): Feedback is generally the receiver’s response to the sender’s message. The sender’s responsibility here is to seek feedback.
• Consider their contribution (D): This is not a standard sender-focused step in the communication process. The sender should consider the receiver’s needs and perspective, but the wording is less precise than the three recognised actions above.

• VLAN 10 for data
• VLAN 20 for voice

• A: Describes physical trunking or logical switch ports, not an SVI.
• B: An SVI can provide management access, but that is only one use—not the best description here.
• D: SVI use is not related to running out of physical ports.

• Create and manage approved IT services as products
• Control which users can deploy those products
• Apply governance, permissions, and constraints
• Use and manage infrastructure-as-code templates, such as AWS CloudFormation templates

• AWS Resource Explorer: Helps find and browse AWS resources; it does not govern IaC deployments.
• AWS Organizations: Manages accounts, consolidated billing, and organization-wide policies.
• AWS Systems Manager: Provides operational management, such as patching, automation, and parameter storage, but it is not primarily used to catalog and govern IaC-based service deployments.

• A is correct: Days beyond the included period incur an extra daily charge.
• D is incorrect: Daily use after 10 days is not free.
• B and C: Data-transfer pricing can depend on the direction and service terms. The exam’s intended distinction is that the included device usage period is the clearly stated no-cost benefit.

• Error correction (ECC): Improves data reliability but does not maximize bandwidth.
• RAM voltage: Increasing voltage may affect stability or speed, but it is not the primary method for increasing module bandwidth.
• Physical module size: Refers to the capacity or form factor of the RAM, not its data-transfer bandwidth.

• Modelo de embeddings multimodal: transforma texto e imagens em vetores no mesmo espaço semântico. Isso permite comparar uma consulta textual com imagens, ou uma imagem com textos relacionados.
• Modelo generativo multimodal: interpreta diferentes modalidades e gera conteúdo, mas não é a escolha específica para indexação e busca vetorial.
• Modelo de geração de imagens: cria imagens, portanto é inadequado.
• Modelo de embeddings de texto: não atende consultas com imagens.

• 255.255.255.128 = /25: 128 total, 126 usable
• 255.255.255.192 = /26: 64 total, 62 usable
• 255.255.255.224 = /27: 32 total, 30 usable
• 255.255.255.240 = /28: 16 total, 14 usable

• One for the network address
• One for the broadcast address

• 8 total addresses
• 6 usable addresses
• Mask: 255.255.255.248

• Honeypots: Decoy systems or services made to attract attackers. Legitimate users should not interact with them, so activity there is a strong indicator of malicious behavior.
• DNS sinkholes: Redirect requests for known malicious domains to a controlled internal system. This can reveal infected hosts attempting to contact command-and-control infrastructure.

• Tokenization: Replaces sensitive data with non-sensitive tokens.
• CI/CD: Automates software development, testing, and deployment.
• Threat modeling: Identifies and analyzes potential threats before or during system design.
• Data obfuscation: Makes data harder to understand or interpret.

• The type of change: standard, normal, or emergency
• The risk, impact, and complexity
• The change model being used

• A standard change may be pre-authorized through its change model.
• A normal change may require assessment and approval by an appropriate change authority.
• An emergency change may be authorized by an emergency change authority, often using an expedited process.

• Change authorities are not only needed for emergency changes.
• They are not assigned only when a change is deployed.
• They are not only required for normal changes.

• Existing measures
• Relationships
• Calculated columns
• Tables and fields
• Existing transformations in the model

• SharePoint folder: Reconnects to the source files. You would likely need to recreate the model and measures.
• Power BI dataflows: Primarily provide reusable data preparation and storage, but they do not automatically provide the existing semantic model and measures.
• Excel workbook: Connects directly to the source file and would also require rebuilding the model and measures.

• SQL injection
• Cross-site scripting (XSS)
• Malicious file uploads
• Common web-application exploits

• Layer 4 firewall: Filters primarily by IP addresses, ports, and transport protocols; it lacks detailed web-application inspection.
• NGFW: Provides advanced network filtering and may include application awareness, but a WAF is more specialized for protecting web applications.
• UTM: Combines several security functions in one device, but it is not specifically focused on web-application attacks.