{"id":19917,"date":"2026-09-23T09:23:33","date_gmt":"2026-09-23T09:23:33","guid":{"rendered":"https:\/\/www.examlabs.com\/certification\/?p=19917"},"modified":"2026-09-23T09:23:33","modified_gmt":"2026-09-23T09:23:33","slug":"huawei-h12-831-practice-test-questions-and-exam-dumps-part20-q381-400","status":"publish","type":"post","link":"https:\/\/www.examlabs.com\/certification\/huawei-h12-831-practice-test-questions-and-exam-dumps-part20-q381-400\/","title":{"rendered":"Huawei H12-831 Practice Test Questions and Exam Dumps Part20 Q381-400"},"content":{"rendered":"

View Full <\/b>Huawei H12-831 Exam Dumps<\/b><\/a> and Practice Test Dumps<\/b><\/h2>\n

 <\/p>\n

Question 381.<\/b><\/p>\n

In OSPF, what is the primary purpose of the SPF algorithm?<\/b><\/p>\n

    \n
  1. <\/b> Calculate the shortest paths through the link-state topology<\/span><\/li>\n
  2. <\/b> Assign IP addresses to interfaces<\/span><\/li>\n
  3. <\/b> Create MPLS labels<\/span><\/li>\n
  4. <\/b> Elect a BGP route reflector<\/span><\/li>\n<\/ol>\n

    Correct Answer: 1. Calculate the shortest paths through the link-state topology<\/b><\/p>\n

    Explanation:<\/b><\/p>\n

    OSPF maintains a link-state database that describes the network topology within an area. The Shortest Path First algorithm processes that database and calculates the lowest-cost paths from the local router to reachable destinations. The resulting routes can then be installed in the routing table. When relevant topology information changes, SPF may run again so forwarding reflects the new network state. The algorithm is central to OSPF path calculation and is unrelated to IP address assignment or MPLS label distribution.<\/span><\/p>\n

    Question 382.<\/b><\/p>\n

    What is the main purpose of an OSPF Area Border Router?<\/b><\/p>\n

      \n
    1. <\/b> Elect the DR on every Ethernet network<\/span><\/li>\n
    2. <\/b> Connect OSPF areas and exchange inter-area routing information<\/span><\/li>\n
    3. <\/b> Provide DHCP services<\/span><\/li>\n
    4. <\/b> Replace the ASBR<\/span><\/li>\n<\/ol>\n

      Correct Answer: 2. Connect OSPF areas and exchange inter-area routing information<\/b><\/p>\n

      Explanation:<\/b><\/p>\n

      An Area Border Router connects multiple OSPF areas and normally provides connectivity between non-backbone areas and Area 0. It maintains separate link-state databases for the areas in which it participates and advertises inter-area reachability between them. ABRs can also perform summarization where appropriate. This hierarchical function helps OSPF scale by limiting detailed topology information to individual areas rather than flooding every internal detail throughout the entire routing domain.<\/span><\/p>\n

      Question 383.<\/b><\/p>\n

      Which OSPF route type includes both the external metric and the internal cost to reach the ASBR?<\/b><\/p>\n

        \n
      1. <\/b> External Type 2<\/span><\/li>\n
      2. <\/b> Inter-area route<\/span><\/li>\n
      3. <\/b> External Type 1<\/span><\/li>\n
      4. <\/b> Intra-area route only<\/span><\/li>\n<\/ol>\n

        Correct Answer: 3. External Type 1<\/b><\/p>\n

        Explanation:<\/b><\/p>\n

        An OSPF External Type 1 route includes the external metric assigned when the route enters OSPF plus the internal OSPF cost required to reach the ASBR. This means routers in different parts of the domain may calculate different total costs for the same external destination. E1 routing is useful when the internal path toward the external exit should influence route selection. E2 routes, by contrast, primarily retain the external metric as their principal cost.<\/span><\/p>\n

        Question 384.<\/b><\/p>\n

        What is the main purpose of an OSPF NSSA?<\/b><\/p>\n

          \n
        1. <\/b> Disable all external routing<\/span><\/li>\n
        2. <\/b> Replace the backbone area<\/span><\/li>\n
        3. <\/b> Convert OSPF into BGP<\/span><\/li>\n
        4. <\/b> Allow a stub-like area to redistribute selected external routes**<\/span><\/li>\n<\/ol>\n

          Correct Answer: 4. Allow a stub-like area to redistribute selected external routes<\/b><\/p>\n

          Explanation:<\/b><\/p>\n

          A Not-So-Stubby Area combines restricted external-route propagation with the ability to introduce external routes locally. An ASBR inside the NSSA advertises those routes using Type 7 LSAs. An appropriate ABR can then translate Type 7 information into Type 5 LSAs for distribution into the wider OSPF domain. NSSAs are useful in branch or limited-area designs where local redistribution is needed without carrying ordinary external LSAs throughout the area.<\/span><\/p>\n

          Question 385.<\/b><\/p>\n

          Which BGP attribute is usually preferred when it has a higher value and is intended to influence outbound path selection inside one AS?<\/b><\/p>\n

            \n
          1. <\/b> Local Preference<\/span><\/li>\n
          2. <\/b> MED<\/span><\/li>\n
          3. <\/b> AS_Path<\/span><\/li>\n
          4. <\/b> Origin<\/span><\/li>\n<\/ol>\n

            Correct Answer: 1. Local Preference<\/b><\/p>\n

            Explanation:<\/b><\/p>\n

            Local Preference is propagated among iBGP routers and is commonly used to determine which external path the local autonomous system should prefer for outbound traffic. Higher values are generally preferred. An organization with multiple upstream providers can assign a higher Local Preference to routes from the primary provider and a lower value to backup routes. This gives administrators predictable control over outbound exit selection without depending on external networks’ routing policies.<\/span><\/p>\n

            Question 386.<\/b><\/p>\n

            What is the primary purpose of the BGP MED attribute?<\/b><\/p>\n

              \n
            1. <\/b> Prevent AS loops<\/span><\/li>\n
            2. <\/b> Suggest a preferred inbound entry point to a neighboring AS<\/span><\/li>\n
            3. <\/b> Replace Local Preference<\/span><\/li>\n
            4. <\/b> Identify the BGP router<\/span><\/li>\n<\/ol>\n

              Correct Answer: 2. Suggest a preferred inbound entry point to a neighboring AS<\/b><\/p>\n

              Explanation:<\/b><\/p>\n

              MED is commonly used when two autonomous systems have multiple interconnections. The advertising AS can assign different MED values to suggest which link the neighboring AS should prefer when sending traffic inward. Lower MED values are normally considered more attractive when compared. MED is advisory rather than mandatory because the neighboring AS can apply its own policies. It therefore influences inbound traffic but does not guarantee a particular remote routing decision.<\/span><\/p>\n

              Question 387.<\/b><\/p>\n

              Why is the BGP AS_Path attribute important for routing security and stability?<\/b><\/p>\n

                \n
              1. <\/b> It provides encryption<\/span><\/li>\n
              2. <\/b> It assigns Route Targets<\/span><\/li>\n
              3. <\/b> It records traversed autonomous systems and helps prevent routing loops<\/span><\/li>\n
              4. <\/b> It creates VRRP groups<\/span><\/li>\n<\/ol>\n

                Correct Answer: 3. It records traversed autonomous systems and helps prevent routing loops<\/b><\/p>\n

                Explanation:<\/b><\/p>\n

                AS_Path lists the autonomous systems through which a BGP advertisement has traveled. When a router receives a route containing its own AS number, it normally rejects the route, which provides an important loop-prevention mechanism. AS_Path length is also considered during best-path selection when earlier decision factors are equal. Administrators can manipulate the path through prepending for traffic engineering, but its fundamental purpose includes recording inter-AS traversal and preventing loops.<\/span><\/p>\n

                Question 388.<\/b><\/p>\n

                What is the primary purpose of a BGP route reflector?<\/b><\/p>\n

                  \n
                1. <\/b> Replace all external BGP peers<\/span><\/li>\n
                2. <\/b> Create MPLS labels<\/span><\/li>\n
                3. <\/b> Provide DHCP redundancy<\/span><\/li>\n
                4. <\/b> Reduce the number of iBGP sessions required in a large AS**<\/span><\/li>\n<\/ol>\n

                  Correct Answer: 4. Reduce the number of iBGP sessions required in a large AS<\/b><\/p>\n

                  Explanation:<\/b><\/p>\n

                  Traditional iBGP requires a full mesh because routes learned from one iBGP peer are not normally advertised to another. A route reflector allows selected routes to be reflected between clients and other peers, reducing the number of sessions required. This improves control-plane scalability in large autonomous systems. Loop-prevention attributes such as Originator_ID and Cluster_List support safe route reflection. Underlying IP reachability is still provided by an IGP or other routing mechanism.<\/span><\/p>\n

                  Question 389.<\/b><\/p>\n

                  In IS-IS, what is the main purpose of Level-1 routing?<\/b><\/p>\n

                    \n
                  1. <\/b> Provide detailed routing within a local IS-IS area<\/span><\/li>\n
                  2. <\/b> Provide internet-wide BGP routing<\/span><\/li>\n
                  3. <\/b> Configure VRRP gateways<\/span><\/li>\n
                  4. <\/b> Distribute MPLS VPN labels<\/span><\/li>\n<\/ol>\n

                    Correct Answer: 1. Provide detailed routing within a local IS-IS area<\/b><\/p>\n

                    Explanation:<\/b><\/p>\n

                    Level-1 IS-IS routers maintain detailed topology information for their own area. They calculate routes to destinations within that area and normally rely on Level-1-2 routers for connectivity toward destinations outside the area. This hierarchical structure limits topology information and helps the network scale. Level-2 routing forms the inter-area backbone, while Level-1 focuses on local-area reachability.<\/span><\/p>\n

                    Question 390.<\/b><\/p>\n

                    What is the main purpose of Level-2 IS-IS routing?<\/b><\/p>\n

                      \n
                    1. <\/b> Assign addresses to hosts<\/span><\/li>\n
                    2. <\/b> Provide inter-area backbone connectivity<\/span><\/li>\n
                    3. <\/b> Elect every DIS<\/span><\/li>\n
                    4. <\/b> Replace all Level-1 routers<\/span><\/li>\n<\/ol>\n

                      Correct Answer: 2. Provide inter-area backbone connectivity<\/b><\/p>\n

                      Explanation:<\/b><\/p>\n

                      Level-2 IS-IS provides backbone-like connectivity between different areas. Level-1-2 routers connect their local Level-1 areas to the Level-2 domain, allowing traffic to move between areas while local routers maintain only the detailed topology they need. Maintaining resilient Level-2 continuity is therefore important for inter-area reachability. Level-2 does not replace Level-1 routing; the two levels work together as part of the hierarchical IS-IS architecture.<\/span><\/p>\n

                      Question 391.<\/b><\/p>\n

                      What is the primary role of LDP in an MPLS network?<\/b><\/p>\n

                        \n
                      1. <\/b> Exchange label bindings associated with forwarding equivalence classes<\/span><\/li>\n
                      2. <\/b> Assign customer IP addresses<\/span><\/li>\n
                      3. <\/b> Elect a VRRP master<\/span><\/li>\n
                      4. <\/b> Create OSPF areas<\/span><\/li>\n<\/ol>\n

                        Correct Answer: 1. Exchange label bindings associated with forwarding equivalence classes<\/b><\/p>\n

                        Explanation:<\/b><\/p>\n

                        Label Distribution Protocol allows MPLS routers to exchange mappings between forwarding equivalence classes and locally assigned labels. These mappings help routers construct label forwarding tables and establish label-switched forwarding behavior. The IGP normally provides underlying IP reachability, while LDP adds the labels required for MPLS transport. LDP therefore complements OSPF or IS-IS rather than replacing them.<\/span><\/p>\n

                        Question 392.<\/b><\/p>\n

                        Which MPLS operation replaces the current top label with another label?<\/b><\/p>\n

                          \n
                        1. <\/b> Push<\/span><\/li>\n
                        2. <\/b> Swap<\/span><\/li>\n
                        3. <\/b> Pop<\/span><\/li>\n
                        4. <\/b> Aggregate<\/span><\/li>\n<\/ol>\n

                          Correct Answer: 2. Swap<\/b><\/p>\n

                          Explanation:<\/b><\/p>\n

                          Label swapping is the normal MPLS forwarding action performed by many transit Label Switching Routers. The router receives a packet with an incoming label, looks up that label in its forwarding table, replaces it with the required outgoing label, and forwards the packet toward the next hop. Push adds labels, while pop removes them. These operations allow MPLS traffic to move efficiently through the provider network.<\/span><\/p>\n

                          Question 393.<\/b><\/p>\n

                          What is the main purpose of a Route Distinguisher in an MPLS Layer 3 VPN?<\/b><\/p>\n

                            \n
                          1. <\/b> Control VRRP mastership<\/span><\/li>\n
                          2. <\/b> Set OSPF cost<\/span><\/li>\n
                          3. <\/b> Make overlapping customer prefixes unique in MP-BGP<\/span><\/li>\n
                          4. <\/b> Select LACP member links<\/span><\/li>\n<\/ol>\n

                            Correct Answer: 3. Make overlapping customer prefixes unique in MP-BGP<\/b><\/p>\n

                            Explanation:<\/b><\/p>\n

                            Customers frequently use overlapping private address spaces. A Route Distinguisher is combined with a customer prefix so that otherwise identical IPv4 routes become unique VPN routes in MP-BGP. This prevents conflicts in the provider control plane. The RD does not determine which VPN should import a route. That function is handled through Route Targets, which provide VPN route-membership policy.<\/span><\/p>\n

                            Question 394.<\/b><\/p>\n

                            Which MPLS VPN mechanism controls route import and export between VPN instances?<\/b><\/p>\n

                              \n
                            1. <\/b> OSPF Router ID<\/span><\/li>\n
                            2. <\/b> LDP priority<\/span><\/li>\n
                            3. <\/b> Ethernet VLAN ID<\/span><\/li>\n
                            4. <\/b> Route Target**<\/span><\/li>\n<\/ol>\n

                              Correct Answer: 4. Route Target<\/b><\/p>\n

                              Explanation:<\/b><\/p>\n

                              Route Targets are extended BGP communities used to control VPN route distribution. A VRF exports routes with selected Route Targets, and another VRF imports those routes when its configured policy matches the associated values. This allows operators to create full-mesh, hub-and-spoke, and shared-services VPN designs. Route Distinguishers ensure route uniqueness, while Route Targets define membership and distribution policy.<\/span><\/p>\n

                              Question 395.<\/b><\/p>\n

                              What is the primary purpose of VRRP?<\/b><\/p>\n

                                \n
                              1. <\/b> Provide a resilient virtual default gateway for hosts<\/span><\/li>\n
                              2. <\/b> Distribute MPLS labels<\/span><\/li>\n
                              3. <\/b> Reflect BGP routes<\/span><\/li>\n
                              4. <\/b> Summarize OSPF prefixes<\/span><\/li>\n<\/ol>\n

                                Correct Answer: 1. Provide a resilient virtual default gateway for hosts<\/b><\/p>\n

                                Explanation:<\/b><\/p>\n

                                VRRP allows multiple routers to present a shared virtual IP address to end hosts. The current master forwards traffic for that gateway, while backup routers monitor the master and can assume responsibility if it fails. Hosts continue using the same configured default gateway, making failover transparent. Features such as tracking and preemption can further improve how VRRP responds to upstream failures and router recovery.<\/span><\/p>\n

                                Question 396.<\/b><\/p>\n

                                What is the benefit of VRRP uplink tracking?<\/b><\/p>\n

                                  \n
                                1. <\/b> It increases Ethernet bandwidth<\/span><\/li>\n
                                2. <\/b> It can lower a master’s effective priority if important upstream connectivity fails<\/span><\/li>\n
                                3. <\/b> It disables failover<\/span><\/li>\n
                                4. <\/b> It creates a BGP community<\/span><\/li>\n<\/ol>\n

                                  Correct Answer: 2. It can lower a master’s effective priority if important upstream connectivity fails<\/b><\/p>\n

                                  Explanation:<\/b><\/p>\n

                                  A router may remain connected to the local LAN even after losing an important upstream interface or route. Without tracking, it could continue acting as VRRP master and attract traffic that it cannot forward successfully. Uplink or route tracking can lower the router’s effective priority, allowing a healthier backup to take over. This makes VRRP failover reflect end-to-end path health rather than only local interface availability.<\/span><\/p>\n

                                  Question 397.<\/b><\/p>\n

                                  What is the primary purpose of LACP in an Eth-Trunk?<\/b><\/p>\n

                                    \n
                                  1. <\/b> Negotiate and monitor member links participating in the aggregation<\/span><\/li>\n
                                  2. <\/b> Configure BGP Local Preference<\/span><\/li>\n
                                  3. <\/b> Assign MPLS Route Targets<\/span><\/li>\n
                                  4. <\/b> Select OSPF areas<\/span><\/li>\n<\/ol>\n

                                    Correct Answer: 1. Negotiate and monitor member links participating in the aggregation<\/b><\/p>\n

                                    Explanation:<\/b><\/p>\n

                                    LACP allows devices at both ends of an aggregated Ethernet connection to exchange control information and determine which physical links should participate actively. It helps detect inconsistent or failed members and can support standby-link behavior. This improves the operational reliability of an Eth-Trunk compared with purely static aggregation. LACP is a Layer 2 link-aggregation mechanism and does not replace routing or MPLS functions.<\/span><\/p>\n

                                    Question 398.<\/b><\/p>\n

                                    Which QoS mechanism is most appropriate when excess traffic should be buffered and transmitted later at a controlled rate?<\/b><\/p>\n

                                      \n
                                    1. <\/b> Traffic policing<\/span><\/li>\n
                                    2. <\/b> Traffic shaping<\/span><\/li>\n
                                    3. <\/b> BFD<\/span><\/li>\n
                                    4. <\/b> Route reflection<\/span><\/li>\n<\/ol>\n

                                      Correct Answer: 2. Traffic shaping<\/b><\/p>\n

                                      Explanation:<\/b><\/p>\n

                                      Traffic shaping regulates the output rate by buffering packets that temporarily exceed a configured rate and transmitting them later as bandwidth becomes available. This smooths bursts and can reduce packet loss, although buffering introduces delay. Policing differs because it normally drops or remarks excess traffic instead of delaying it. Shaping is useful when a network wants to conform traffic to a rate while preserving as many packets as practical.<\/span><\/p>\n

                                      Question 399.<\/b><\/p>\n

                                      Which technology can provide rapid forwarding-path failure detection for routing protocols such as OSPF, IS-IS, and BGP?<\/b><\/p>\n

                                        \n
                                      1. <\/b> BFD<\/span><\/li>\n
                                      2. <\/b> DHCP relay<\/span><\/li>\n
                                      3. <\/b> Route Distinguisher<\/span><\/li>\n
                                      4. <\/b> STP only<\/span><\/li>\n<\/ol>\n

                                        Correct Answer: 1. BFD<\/b><\/p>\n

                                        Explanation:<\/b><\/p>\n

                                        Bidirectional Forwarding Detection is designed to identify forwarding-path failures quickly. Routing protocols can associate with BFD sessions and react when BFD reports that a neighbor or path is no longer reachable. This can significantly reduce failure-detection time compared with relying only on default routing-protocol timers. BFD does not calculate alternate routes itself; it supplies fast liveness information so the routing protocol can begin convergence sooner.<\/span><\/p>\n

                                        Question 400.<\/b><\/p>\n

                                        Which design approach BEST supports scalability, resiliency, and predictable operations in a large Huawei network?<\/b><\/p>\n

                                          \n
                                        1. <\/b> Redistribute all routes between every protocol without filtering<\/span><\/li>\n
                                        2. <\/b> Depend on a single path for all critical traffic<\/span><\/li>\n
                                        3. <\/b> Avoid summarization and route policy<\/span><\/li>\n
                                        4. <\/b> Use hierarchical routing, structured addressing, controlled policies, summarization, redundant paths, fast failure detection, and continuous monitoring**<\/span><\/li>\n<\/ol>\n

                                          Correct Answer: 4. Use hierarchical routing, structured addressing, controlled policies, summarization, redundant paths, fast failure detection, and continuous monitoring<\/b><\/p>\n

                                          Explanation:<\/b><\/p>\n

                                          Large networks are most manageable when every technology has a clearly defined role. Hierarchical routing reduces topology scope, structured addressing enables summarization, and explicit route policy prevents unintended propagation. Redundant links, VRRP, Eth-Trunk, and BFD improve availability and convergence. MPLS can provide scalable service transport, while QoS protects critical traffic during congestion. Continuous monitoring and regular failover testing help verify that these mechanisms work together predictably under both normal and failure conditions.<\/span><\/p>\n

                                           <\/p>\n","protected":false},"excerpt":{"rendered":"

                                          View Full Huawei H12-831 Exam Dumps and Practice Test Dumps   Question 381. In OSPF, what is the primary purpose of the SPF algorithm? Calculate the shortest paths through the link-state topology Assign IP addresses to interfaces Create MPLS labels Elect a BGP route reflector Correct Answer: 1. Calculate the shortest paths through the link-state […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":[],"categories":[1648,1647],"tags":[],"_links":{"self":[{"href":"https:\/\/www.examlabs.com\/certification\/wp-json\/wp\/v2\/posts\/19917"}],"collection":[{"href":"https:\/\/www.examlabs.com\/certification\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.examlabs.com\/certification\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.examlabs.com\/certification\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.examlabs.com\/certification\/wp-json\/wp\/v2\/comments?post=19917"}],"version-history":[{"count":1,"href":"https:\/\/www.examlabs.com\/certification\/wp-json\/wp\/v2\/posts\/19917\/revisions"}],"predecessor-version":[{"id":19918,"href":"https:\/\/www.examlabs.com\/certification\/wp-json\/wp\/v2\/posts\/19917\/revisions\/19918"}],"wp:attachment":[{"href":"https:\/\/www.examlabs.com\/certification\/wp-json\/wp\/v2\/media?parent=19917"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.examlabs.com\/certification\/wp-json\/wp\/v2\/categories?post=19917"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.examlabs.com\/certification\/wp-json\/wp\/v2\/tags?post=19917"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}