{"id":21117,"date":"2026-09-24T10:53:04","date_gmt":"2026-09-24T10:53:04","guid":{"rendered":"https:\/\/www.examlabs.com\/certification\/?p=21117"},"modified":"2026-09-24T10:53:04","modified_gmt":"2026-09-24T10:53:04","slug":"huawei-h12-821-practice-test-questions-and-exam-dumps-part12-q221-240","status":"publish","type":"post","link":"https:\/\/www.examlabs.com\/certification\/huawei-h12-821-practice-test-questions-and-exam-dumps-part12-q221-240\/","title":{"rendered":"Huawei H12-821 Practice Test Questions and Exam Dumps Part12 Q221-240"},"content":{"rendered":"<p><b>View Full <\/b><a href=\"https:\/\/www.examlabs.com\/h12-821-exam-dumps\"><b>Huawei H12-821 Exam Dumps<\/b><\/a><b> and Practice Test Dumps.<\/b><\/p>\n<p><b><br \/>\n<\/b><b>Question 221. In a BGP\/MPLS Layer 3 VPN, which protocol is primarily used between PE routers to exchange VPN routes?<\/b><\/p>\n<ol>\n<li><b><\/b><span style=\"font-weight: 400;\"> STP<\/span><\/li>\n<li><b><\/b><span style=\"font-weight: 400;\"> DHCP<\/span><\/li>\n<li><b><\/b><span style=\"font-weight: 400;\"> MP-BGP<\/span><\/li>\n<li><b><\/b><span style=\"font-weight: 400;\"> VRRP<\/span><\/li>\n<\/ol>\n<p><b>Correct Answer: 3. MP-BGP<\/b><\/p>\n<p><b>Explanation:<\/b><\/p>\n<p><span style=\"font-weight: 400;\">BGP\/MPLS Layer 3 VPN uses Multiprotocol BGP (MP-BGP) between Provider Edge routers to distribute VPN routing information. After a PE learns an ordinary IPv4 route from a directly connected CE, it associates the route with VPN-specific information such as a Route Distinguisher and VPN Target. The resulting VPN-IPv4 route can then be advertised to remote PEs through MP-BGP. Huawei describes MP-BGP as the mechanism used across the service-provider backbone to exchange these VPN routes, while MPLS provides the corresponding data-plane forwarding service.<\/span><\/p>\n<p><b>Question 222. What type of route does a CE normally advertise to its directly connected PE in an IPv4 MPLS L3VPN?<\/b><\/p>\n<ol>\n<li><b><\/b><span style=\"font-weight: 400;\"> A standard IPv4 route<\/span><\/li>\n<li><b><\/b><span style=\"font-weight: 400;\"> A VPN-IPv4 route containing an RD<\/span><\/li>\n<li><b><\/b><span style=\"font-weight: 400;\"> An MPLS label-only route<\/span><\/li>\n<li><b><\/b><span style=\"font-weight: 400;\"> An EVPN MAC\/IP route<\/span><\/li>\n<\/ol>\n<p><b>Correct Answer: 1. A standard IPv4 route<\/b><\/p>\n<p><b>Explanation:<\/b><\/p>\n<p><span style=\"font-weight: 400;\">The CE normally has no awareness of the provider&#8217;s internal MPLS VPN mechanisms. It exchanges standard IPv4 routes with the directly connected PE using a supported routing method such as static routing, OSPF, IS-IS, RIP, or BGP. After receiving the customer route, the PE stores it in the appropriate VPN instance and adds the Route Distinguisher to form a VPN-IPv4 route for distribution across the provider backbone. This separation allows ordinary customer routing equipment to participate without supporting the MPLS VPN control plane itself.<\/span><\/p>\n<p><b>Question 223. After a PE learns an IPv4 customer route from a CE, what is added to make the route unique for MP-BGP VPN distribution?<\/b><\/p>\n<ol>\n<li><b><\/b><span style=\"font-weight: 400;\"> An STP bridge ID<\/span><\/li>\n<li><b><\/b><span style=\"font-weight: 400;\"> A DHCP transaction ID<\/span><\/li>\n<li><b><\/b><span style=\"font-weight: 400;\"> A VRRP virtual address<\/span><\/li>\n<li><b><\/b><span style=\"font-weight: 400;\"> A Route Distinguisher<\/span><\/li>\n<\/ol>\n<p><b>Correct Answer: 4. A Route Distinguisher<\/b><\/p>\n<p><b>Explanation:<\/b><\/p>\n<p><span style=\"font-weight: 400;\">After a PE receives a standard IPv4 customer route, it associates that route with the configured Route Distinguisher (RD) of the VPN instance. The combination creates a VPN-IPv4 route that is unique even if another customer uses exactly the same IPv4 prefix. This is essential because overlapping private address space is common in MPLS VPN deployments. The RD solves the uniqueness problem in the MP-BGP VPN routing system, while VPN Targets determine which VPN instances are allowed to import or export the resulting routes.<\/span><\/p>\n<p><b>Question 224. Which additional information can an ingress PE advertise with a VPN-IPv4 route to a remote PE?<\/b><\/p>\n<ol>\n<li><b><\/b><span style=\"font-weight: 400;\"> STP root priority only<\/span><\/li>\n<li><b><\/b><span style=\"font-weight: 400;\"> VPN Target information and an MPLS label<\/span><\/li>\n<li><b><\/b><span style=\"font-weight: 400;\"> DHCP lease duration only<\/span><\/li>\n<li><b><\/b><span style=\"font-weight: 400;\"> Only the physical CE interface number<\/span><\/li>\n<\/ol>\n<p><b>Correct Answer: 2. VPN Target information and an MPLS label<\/b><\/p>\n<p><b>Explanation:<\/b><\/p>\n<p><span style=\"font-weight: 400;\">Huawei describes the ingress PE as advertising the VPN-IPv4 route through MP-BGP together with information including an Export VPN Target and an MPLS label. The VPN Target is used by remote PEs to determine whether the route belongs in one of their VPN instances. The label supplies VPN-related forwarding information for the data plane. The remote PE can therefore make both a control-plane import decision and a forwarding decision using the attributes distributed with the VPN route. This is a key distinction between ordinary IPv4 BGP routing and MPLS VPN route distribution.<\/span><\/p>\n<p><b>Question 225. What condition is normally required before a remote PE can install a received VPN route into a local VPN instance?<\/b><\/p>\n<ol>\n<li><b><\/b><span style=\"font-weight: 400;\"> The CE must run MPLS<\/span><\/li>\n<li><b><\/b><span style=\"font-weight: 400;\"> The route must have no RD<\/span><\/li>\n<li><b><\/b><span style=\"font-weight: 400;\"> The P router must be a CE<\/span><\/li>\n<li><b><\/b><span style=\"font-weight: 400;\"> The route&#8217;s VPN Target must satisfy the local import policy and its next hop must be reachable<\/span><\/li>\n<\/ol>\n<p><b>Correct Answer: 4. The route&#8217;s VPN Target must satisfy the local import policy and its next hop must be reachable<\/b><\/p>\n<p><b>Explanation:<\/b><\/p>\n<p><span style=\"font-weight: 400;\">A remote PE does not automatically install every VPN route received through MP-BGP into every VPN instance. It examines VPN Target information and performs the appropriate route import checks. The route must match the receiving VPN instance&#8217;s import policy, and the route&#8217;s next hop must also be resolvable so traffic can reach the advertising PE. Huawei describes this process as route crossing, tunnel recursion, and route selection before the VPN route is finally installed into the VPN routing table. This mechanism preserves customer isolation while permitting selective VPN connectivity.<\/span><\/p>\n<p><b>Question 226. Which statement BEST describes the role of a PE router in a BGP\/MPLS L3VPN?<\/b><\/p>\n<ol>\n<li><b><\/b><span style=\"font-weight: 400;\"> It has no knowledge of customer VPN information<\/span><\/li>\n<li><b><\/b><span style=\"font-weight: 400;\"> It operates only as an Ethernet bridge<\/span><\/li>\n<li><b><\/b><span style=\"font-weight: 400;\"> It maintains VPN-specific routing information and connects customer sites to the provider backbone<\/span><\/li>\n<li><b><\/b><span style=\"font-weight: 400;\"> It must always act as the customer CE<\/span><\/li>\n<\/ol>\n<p><b>Correct Answer: 3. It maintains VPN-specific routing information and connects customer sites to the provider backbone<\/b><\/p>\n<p><b>Explanation:<\/b><\/p>\n<p><span style=\"font-weight: 400;\">The Provider Edge router is where customer VPN processing occurs. It directly connects to one or more CE devices, maintains VPN instances, learns customer routes, converts those routes into VPN routing information, exchanges VPN routes with remote PEs, and applies MPLS VPN forwarding. Huawei contrasts this with P routers, which operate inside the provider backbone and generally do not connect directly to customer CEs or maintain customer-specific VPN instances. Because of these responsibilities, the PE performs much of the control-plane and service-edge processing in an MPLS L3VPN architecture.<\/span><\/p>\n<p><b>Question 227. Which device normally does NOT need to maintain individual customer VPN routing tables in a basic MPLS L3VPN?<\/b><\/p>\n<ol>\n<li><b><\/b><span style=\"font-weight: 400;\"> Provider (P) router<\/span><\/li>\n<li><b><\/b><span style=\"font-weight: 400;\"> Provider Edge router<\/span><\/li>\n<li><b><\/b><span style=\"font-weight: 400;\"> Customer Edge router<\/span><\/li>\n<li><b><\/b><span style=\"font-weight: 400;\"> Route reflector acting for VPNv4 routes<\/span><\/li>\n<\/ol>\n<p><b>Correct Answer: 1. Provider (P) router<\/b><\/p>\n<p><b>Explanation:<\/b><\/p>\n<p><span style=\"font-weight: 400;\">A P router operates in the provider backbone and normally forwards MPLS traffic without maintaining each customer&#8217;s VPN routing table. Customer-specific VPN processing takes place primarily on the PE routers. The P router needs sufficient underlay and MPLS forwarding information to transport labeled traffic between PEs, but it does not normally connect directly to customer CE devices or process customer VPN instances. This separation is a major scalability advantage of BGP\/MPLS L3VPN because the service-provider core can transport many VPNs without every core router learning every customer prefix.<\/span><\/p>\n<p><b>Question 228. Which routing methods can be used between a PE and a CE in a Huawei MPLS L3VPN?<\/b><\/p>\n<ol>\n<li><b><\/b><span style=\"font-weight: 400;\"> Only BGP<\/span><\/li>\n<li><b><\/b><span style=\"font-weight: 400;\"> BGP, an IGP, or static routing as appropriate<\/span><\/li>\n<li><b><\/b><span style=\"font-weight: 400;\"> Only OSPF<\/span><\/li>\n<li><b><\/b><span style=\"font-weight: 400;\"> Only MPLS LDP<\/span><\/li>\n<\/ol>\n<p><b>Correct Answer: 2. BGP, an IGP, or static routing as appropriate<\/b><\/p>\n<p><b>Explanation:<\/b><\/p>\n<p><span style=\"font-weight: 400;\">Huawei supports multiple methods for PE-CE route exchange. Depending on the deployment, the PE and CE can use BGP, an Interior Gateway Protocol, or static routing, including a default route. This provides flexibility because customer sites differ in complexity and operational requirements. A small branch may need only a static or default route, while a larger enterprise site may run OSPF or BGP with the PE. Regardless of the PE-CE routing method, the CE exchanges conventional customer routes; the PE handles the conversion into VPN routing information for transport across the MPLS backbone.<\/span><\/p>\n<p><b>Question 229. Why does a CE normally not need to support MPLS in a basic BGP\/MPLS L3VPN?<\/b><\/p>\n<ol>\n<li><b><\/b><span style=\"font-weight: 400;\"> MPLS VPN processing is handled by the provider-side PE and backbone<\/span><\/li>\n<li><b><\/b><span style=\"font-weight: 400;\"> MPLS can operate only on hosts<\/span><\/li>\n<li><b><\/b><span style=\"font-weight: 400;\"> The CE exchanges only Layer 2 BPDUs<\/span><\/li>\n<li><b><\/b><span style=\"font-weight: 400;\"> The CE must use VXLAN instead<\/span><\/li>\n<\/ol>\n<p><b>Correct Answer: 1. MPLS VPN processing is handled by the provider-side PE and backbone<\/b><\/p>\n<p><b>Explanation:<\/b><\/p>\n<p><span style=\"font-weight: 400;\">In a standard MPLS L3VPN model, the CE sees an ordinary Layer 3 connection to the service provider. It exchanges normal IP routes with the attached PE and forwards normal IP packets toward that PE. The PE then performs VPN-instance lookup, VPN route processing, and MPLS encapsulation required to transport the customer&#8217;s traffic across the provider network. Huawei explicitly notes that the CE usually does not perceive the existence of the VPN and does not need MPLS functionality. This simplifies customer-site requirements and keeps MPLS complexity within the provider domain.<\/span><\/p>\n<p><b>Question 230. In a Huawei VPN instance configuration, what is the effect of using <\/b><b>vpn-target 100:1 both<\/b><b>?<\/b><\/p>\n<ol>\n<li><b><\/b><span style=\"font-weight: 400;\"> It configures only an RD<\/span><\/li>\n<li><b><\/b><span style=\"font-weight: 400;\"> It disables route exchange<\/span><\/li>\n<li><b><\/b><span style=\"font-weight: 400;\"> It configures only the export target<\/span><\/li>\n<li><b><\/b><span style=\"font-weight: 400;\"> It applies the specified VPN Target to both import and export operations<\/span><\/li>\n<\/ol>\n<p><b>Correct Answer: 4. It applies the specified VPN Target to both import and export operations<\/b><\/p>\n<p><b>Explanation:<\/b><\/p>\n<p><span style=\"font-weight: 400;\">The <\/span><span style=\"font-weight: 400;\">both<\/span><span style=\"font-weight: 400;\"> keyword means the specified VPN Target is used for both export and import behavior in the VPN instance. Routes exported from the VPN can carry that RT, and routes received with a matching RT can be imported into the VPN according to the configured policy. Huawei configuration examples commonly use a command such as <\/span><span style=\"font-weight: 400;\">vpn-target 100:1 both<\/span><span style=\"font-weight: 400;\"> when two sites belong to the same VPN and should exchange routes symmetrically. More complex designs can configure different import and export targets to implement hub-and-spoke or controlled inter-VPN connectivity.<\/span><\/p>\n<p><b>Question 231. What must be configured between two PEs so they can exchange IPv4 VPN routes using MP-BGP?<\/b><\/p>\n<ol>\n<li><b><\/b><span style=\"font-weight: 400;\"> An STP adjacency<\/span><\/li>\n<li><b><\/b><span style=\"font-weight: 400;\"> A VPNv4 BGP peer relationship with the peer enabled in the VPNv4 address family<\/span><\/li>\n<li><b><\/b><span style=\"font-weight: 400;\"> A DHCP relay relationship<\/span><\/li>\n<li><b><\/b><span style=\"font-weight: 400;\"> An IGMP snooping instance<\/span><\/li>\n<\/ol>\n<p><b>Correct Answer: 2. A VPNv4 BGP peer relationship with the peer enabled in the VPNv4 address family<\/b><\/p>\n<p><b>Explanation:<\/b><\/p>\n<p><span style=\"font-weight: 400;\">To exchange VPN-IPv4 routes, the PEs need a BGP peer relationship and must enable that peer within the VPNv4 address family. Huawei configuration procedures explicitly enter the <\/span><span style=\"font-weight: 400;\">ipv4-family vpnv4<\/span><span style=\"font-weight: 400;\"> view and then enable the specified peer for VPNv4 route exchange. Establishing an ordinary IPv4 unicast BGP relationship alone is not enough to exchange VPNv4 NLRI. The PEs also need underlying IP reachability so their BGP session can form and a usable transport tunnel so VPN data traffic can subsequently cross the provider backbone.<\/span><\/p>\n<p><b>Question 232. Why are PE loopback interfaces commonly used as BGP peer endpoints in an MPLS backbone?<\/b><\/p>\n<ol>\n<li><b><\/b><span style=\"font-weight: 400;\"> Loopbacks automatically create VPN Targets<\/span><\/li>\n<li><b><\/b><span style=\"font-weight: 400;\"> Loopbacks disable MPLS<\/span><\/li>\n<li><b><\/b><span style=\"font-weight: 400;\"> A loopback provides a stable logical endpoint that is less dependent on the state of one physical interface<\/span><\/li>\n<li><b><\/b><span style=\"font-weight: 400;\"> BGP cannot use physical interfaces<\/span><\/li>\n<\/ol>\n<p><b>Correct Answer: 3. A loopback provides a stable logical endpoint that is less dependent on the state of one physical interface<\/b><\/p>\n<p><b>Explanation:<\/b><\/p>\n<p><span style=\"font-weight: 400;\">Loopback interfaces are widely used as routing-protocol and BGP peer endpoints because they remain logically available as long as the router itself is operational and the routing system can reach the loopback address. A physical interface address, by contrast, becomes unavailable when that specific interface fails. Huawei L3VPN examples commonly establish PE-to-PE BGP sessions through loopback reachability provided by the backbone IGP. This design improves resilience and separates the control-plane session endpoint from any single physical transport link, especially when multiple paths exist between PEs.<\/span><\/p>\n<p><b>Question 233. What is the PRIMARY purpose of the provider backbone IGP in a conventional MPLS L3VPN?<\/b><\/p>\n<ol>\n<li><b><\/b><span style=\"font-weight: 400;\"> To provide underlay IP reachability between provider routers and PE loopbacks<\/span><\/li>\n<li><b><\/b><span style=\"font-weight: 400;\"> To advertise customer VPN routes directly to CEs in all sites<\/span><\/li>\n<li><b><\/b><span style=\"font-weight: 400;\"> To replace MP-BGP VPN route exchange<\/span><\/li>\n<li><b><\/b><span style=\"font-weight: 400;\"> To assign VPN Targets<\/span><\/li>\n<\/ol>\n<p><b>Correct Answer: 4. To provide underlay IP reachability between provider routers and PE loopbacks<\/b><\/p>\n<p><b>Explanation:<\/b><\/p>\n<p><span style=\"font-weight: 400;\">The provider&#8217;s IGP, such as OSPF or IS-IS, supplies the underlay reachability required for the MPLS backbone. Provider routers need routes to infrastructure addresses such as PE and P-router loopbacks so MPLS LSPs and BGP sessions can operate. Customer VPN prefixes are normally distributed between PEs using MP-BGP rather than injected wholesale into the provider IGP. Keeping customer routes out of the backbone IGP improves scalability and maintains a clean separation between infrastructure reachability and VPN service routes. Huawei L3VPN configuration procedures therefore establish IGP reachability before building MPLS and MP-BGP services.<\/span><\/p>\n<p><b>Question 234. What happens if the import VPN Target on a remote PE does not match the export VPN Target attached to a received VPN route?<\/b><\/p>\n<ol>\n<li><b><\/b><span style=\"font-weight: 400;\"> The route is not imported into that VPN instance based on the RT relationship<\/span><\/li>\n<li><b><\/b><span style=\"font-weight: 400;\"> The route automatically becomes a public route<\/span><\/li>\n<li><b><\/b><span style=\"font-weight: 400;\"> The remote PE changes the route&#8217;s RD<\/span><\/li>\n<li><b><\/b><span style=\"font-weight: 400;\"> The route is converted into an OSPF Type 1 LSA<\/span><\/li>\n<\/ol>\n<p><b>Correct Answer: 1. The route is not imported into that VPN instance based on the RT relationship<\/b><\/p>\n<p><b>Explanation:<\/b><\/p>\n<p><span style=\"font-weight: 400;\">VPN Targets control membership and route distribution between VPN instances. When a remote PE receives a VPN route, it compares the route&#8217;s exported RT values with the import RT values of its local VPN instances. If there is no appropriate match, that VPN instance does not import the route. This mechanism allows the provider to maintain strong logical separation even though all VPN routes may be exchanged through the same MP-BGP infrastructure. Administrators can intentionally use different import and export RT combinations to create complex VPN topologies without changing the customer&#8217;s IP prefixes.<\/span><\/p>\n<p><b>Question 235. Why are Route Targets classified as BGP extended communities?<\/b><\/p>\n<ol>\n<li><b><\/b><span style=\"font-weight: 400;\"> They are physical interface identifiers<\/span><\/li>\n<li><b><\/b><span style=\"font-weight: 400;\"> They are MPLS transport labels<\/span><\/li>\n<li><b><\/b><span style=\"font-weight: 400;\"> They are attributes carried with BGP VPN routes to express VPN routing policy<\/span><\/li>\n<li><b><\/b><span style=\"font-weight: 400;\"> They replace the IPv4 destination prefix<\/span><\/li>\n<\/ol>\n<p><b>Correct Answer: 3. They are attributes carried with BGP VPN routes to express VPN routing policy<\/b><\/p>\n<p><b>Explanation:<\/b><\/p>\n<p><span style=\"font-weight: 400;\">A Route Target is implemented as a BGP extended community associated with VPN routing information. Because it travels as an attribute with the VPN route, remote PEs can examine the RT and determine whether the route should be imported into a local VPN instance. This creates flexible policy without requiring unique routing protocols for every customer. Multiple RTs can also be associated with routes where more sophisticated connectivity is required. Route Targets therefore control VPN route membership, whereas Route Distinguishers are used to make otherwise overlapping routes unique in the VPN address family.<\/span><\/p>\n<p><b>Question 236. What is a key reason MP-BGP is used instead of ordinary IPv4 BGP for MPLS VPN route exchange?<\/b><\/p>\n<ol>\n<li><b><\/b><span style=\"font-weight: 400;\"> Ordinary BGP cannot use TCP<\/span><\/li>\n<li><b><\/b><span style=\"font-weight: 400;\"> MP-BGP can carry VPN-specific address families and additional attributes needed for VPN route distribution<\/span><\/li>\n<li><b><\/b><span style=\"font-weight: 400;\"> MP-BGP automatically encrypts customer traffic<\/span><\/li>\n<li><b><\/b><span style=\"font-weight: 400;\"> MP-BGP replaces MPLS forwarding<\/span><\/li>\n<\/ol>\n<p><b>Correct Answer: 2. MP-BGP can carry VPN-specific address families and additional attributes needed for VPN route distribution<\/b><\/p>\n<p><b>Explanation:<\/b><\/p>\n<p><span style=\"font-weight: 400;\">MPLS L3VPN requires more information than an ordinary IPv4 destination prefix. The control plane must distinguish overlapping customer prefixes and distribute attributes such as Route Targets and VPN-related labels. MP-BGP extends BGP so it can carry additional address families, including VPNv4 routes. This allows one BGP infrastructure to transport routing information for many logically separate VPNs. MPLS remains responsible for the labeled data-plane transport, while MP-BGP handles VPN routing information in the control plane. The two technologies therefore perform complementary rather than interchangeable roles.<\/span><\/p>\n<p><b>Question 237. Which statement BEST describes Inter-AS VPN Option B?<\/b><\/p>\n<ol>\n<li><b><\/b><span style=\"font-weight: 400;\"> ASBRs never exchange VPN routes<\/span><\/li>\n<li><b><\/b><span style=\"font-weight: 400;\"> Every customer requires a dedicated physical ASBR interface<\/span><\/li>\n<li><b><\/b><span style=\"font-weight: 400;\"> Only ordinary IPv4 routes are exchanged between ASBRs<\/span><\/li>\n<li><b><\/b><span style=\"font-weight: 400;\"> ASBRs exchange VPNv4 routes using MP-EBGP without requiring a VPN instance for each customer on the ASBR<\/span><\/li>\n<\/ol>\n<p><b>Correct Answer: 4. ASBRs exchange VPNv4 routes using MP-EBGP without requiring a VPN instance for each customer on the ASBR<\/b><\/p>\n<p><b>Explanation:<\/b><\/p>\n<p><span style=\"font-weight: 400;\">Huawei&#8217;s Inter-AS VPN Option B allows ASBRs in different provider autonomous systems to establish an MP-EBGP relationship and exchange VPN-IPv4 routes. Unlike approaches that require per-VPN subinterfaces or VPN instances on the ASBR, Option B avoids configuring a customer VPN instance for every VPN on the ASBR. However, the ASBR must maintain and advertise VPNv4 routes, so its VPN routing scale remains an important design consideration. This approach can be useful when a provider VPN service spans multiple autonomous systems and dedicated interfaces for each VPN are impractical.<\/span><\/p>\n<p><b>Question 238. What is an important scalability advantage of Inter-AS VPN Option C compared with Option B in environments containing very large numbers of VPN routes?<\/b><\/p>\n<ol>\n<li><b><\/b><span style=\"font-weight: 400;\"> It removes BGP completely<\/span><\/li>\n<li><b><\/b><span style=\"font-weight: 400;\"> It helps prevent ASBRs from becoming VPN-route bottlenecks by allowing PEs in different ASs to exchange VPN routes more directly<\/span><\/li>\n<li><b><\/b><span style=\"font-weight: 400;\"> It requires every CE to support MPLS<\/span><\/li>\n<li><b><\/b><span style=\"font-weight: 400;\"> It disables labeled routes between autonomous systems<\/span><\/li>\n<\/ol>\n<p><b>Correct Answer: 2. It helps prevent ASBRs from becoming VPN-route bottlenecks by allowing PEs in different ASs to exchange VPN routes more directly<\/b><\/p>\n<p><b>Explanation:<\/b><\/p>\n<p><span style=\"font-weight: 400;\">Huawei identifies Inter-AS VPN Option C as useful when large numbers of VPN routes must cross autonomous-system boundaries. In Option B, ASBRs maintain and advertise the VPNv4 routes, which can make them scalability bottlenecks. Option C establishes the required labeled public-network reachability between autonomous systems and allows PEs in different ASs to establish multi-hop MP-EBGP relationships for VPN route exchange. This reduces VPN route-processing pressure on the ASBRs and improves scalability for large provider deployments, although the design is more complex than simpler inter-AS approaches.<\/span><\/p>\n<p><b>Question 239. After a PE interface is bound to a VPN instance, what configuration concern should an administrator remember?<\/b><\/p>\n<ol>\n<li><b><\/b><span style=\"font-weight: 400;\"> Layer 3 settings such as the interface IP address may need to be configured again<\/span><\/li>\n<li><b><\/b><span style=\"font-weight: 400;\"> The interface can no longer run any routing protocol<\/span><\/li>\n<li><b><\/b><span style=\"font-weight: 400;\"> The VPN instance is automatically deleted<\/span><\/li>\n<li><b><\/b><span style=\"font-weight: 400;\"> The CE must immediately enable MPLS<\/span><\/li>\n<\/ol>\n<p><b>Correct Answer: 1. Layer 3 settings such as the interface IP address may need to be configured again<\/b><\/p>\n<p><b>Explanation:<\/b><\/p>\n<p><span style=\"font-weight: 400;\">Huawei warns that binding a PE interface to a VPN instance changes the interface&#8217;s Layer 3 context and can remove existing Layer 3 configuration, including IP addressing and routing-protocol settings. A common configuration sequence is therefore to first bind the interface to the required VPN instance and then configure the customer-facing IP address and any PE-CE routing protocol. Forgetting this behavior can produce a confusing outage because the interface may remain physically Up while losing the Layer 3 parameters required to communicate with the CE.<\/span><\/p>\n<p><b>Question 240. A provider must connect two customer sites using an MPLS L3VPN. Both customers may use overlapping address space, P routers should remain unaware of customer routes, and only sites with matching VPN policy should exchange routes. Which design BEST satisfies these requirements?<\/b><\/p>\n<ol>\n<li><b><\/b><span style=\"font-weight: 400;\"> Put every customer route into the provider IGP<\/span><\/li>\n<li><b><\/b><span style=\"font-weight: 400;\"> Configure one global IP routing table on all PEs and P routers<\/span><\/li>\n<li><b><\/b><span style=\"font-weight: 400;\"> Use separate PE VPN instances, RDs for route uniqueness, RTs for import\/export policy, MP-BGP between PEs, and MPLS transport across the core<\/span><\/li>\n<li><b><\/b><span style=\"font-weight: 400;\"> Use STP and VLANs only across the entire provider backbone<\/span><\/li>\n<\/ol>\n<p><b>Correct Answer: 3. Use separate PE VPN instances, RDs for route uniqueness, RTs for import\/export policy, MP-BGP between PEs, and MPLS transport across the core<\/b><\/p>\n<p><b>Explanation:<\/b><\/p>\n<p><span style=\"font-weight: 400;\">This design follows the core BGP\/MPLS L3VPN architecture. Separate VPN instances isolate customer routing information on the PE. Route Distinguishers make overlapping customer prefixes unique when represented as VPN routes, and Route Targets determine which VPN instances are allowed to exchange those routes. MP-BGP distributes VPN routing information between PEs, while MPLS transports customer packets across the provider backbone. Core P routers therefore need infrastructure and MPLS forwarding information but do not need each customer&#8217;s VPN routing table. This division provides isolation, overlapping-address support, policy-controlled connectivity, and scalable provider-core operation.<\/span><\/p>\n","protected":false},"excerpt":{"rendered":"<p>View Full Huawei H12-821 Exam Dumps and Practice Test Dumps. Question 221. In a BGP\/MPLS Layer 3 VPN, which protocol is primarily used between PE routers to exchange VPN routes? STP DHCP MP-BGP VRRP Correct Answer: 3. MP-BGP Explanation: BGP\/MPLS Layer 3 VPN uses Multiprotocol BGP (MP-BGP) between Provider Edge routers to distribute VPN routing [&hellip;]<\/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\/21117"}],"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=21117"}],"version-history":[{"count":1,"href":"https:\/\/www.examlabs.com\/certification\/wp-json\/wp\/v2\/posts\/21117\/revisions"}],"predecessor-version":[{"id":21118,"href":"https:\/\/www.examlabs.com\/certification\/wp-json\/wp\/v2\/posts\/21117\/revisions\/21118"}],"wp:attachment":[{"href":"https:\/\/www.examlabs.com\/certification\/wp-json\/wp\/v2\/media?parent=21117"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.examlabs.com\/certification\/wp-json\/wp\/v2\/categories?post=21117"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.examlabs.com\/certification\/wp-json\/wp\/v2\/tags?post=21117"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}