Free Practice Questions for Huawei H12-891_V1.0 Exam

EVPN Route Types:

Type 1 (MAC/IP Advertisement Route): Advertises host MAC and IP information — used.

Type 2 (MAC/IP Advertisement Route): Advertises MAC + IP binding for end hosts — used.

Type 3 (Inclusive Multicast Ethernet Tag Route): Used to advertise VXLAN multicast group info — used.

Type 4 (Ethernet Segment Route): Used in multi-homing scenarios, especially in DC (data center) environments, to coordinate DF election — typically not used in campus VXLAN.

So in campus virtualized networks, which are often single-homed, Type 4 is not required.

Correct answer: C. Type 4

Huawei’s NQA (Network Quality Analysis) provides tools to test and monitor network performance such as latency, jitter, and packet loss. The supported test types include:

ICMP — For reachability and round-trip time testing.

UDP, TCP, HTTP, FTP, etc.

DNS, VoIP, DHCP (limited to simulation, not monitoring protocol status itself)

Protocols like SNMP and OSPF are not directly monitored by NQA, as these are management or control plane protocols, not data-path or performance-measurable protocols.

Correct answer: C. ICMP

The basic constructs in YANG data modeling include:

Leaf node – A single data element with a specific type (e.g., integer, string).

List node – A repeating set of elements, each structured the same.

Incorrect options:

A. Set node – ❌ Not a valid YANG construct.

D. Tree node – ❌ Not an individual data model element. The entire model forms a tree structure, but there is no “tree node” in YANG syntax.

Exact Extract – Huawei YANG Modeling Fundamentals:

“YANG defines elements such as leaf, list, container, choice, and leaf-list. ' Set ' and ' tree ' are not YANG node types.”

In BGP4+ (used for IPv6 routing), the MP_REACH_NLRI attribute is used to advertise reachable routes. The Next Hop field must:

Contain a global unicast IPv6 address

Link-local addresses are not used in MP_REACH_NLRI because they are valid only on a local link and not suitable for inter-AS routing.

RFC 2545 (Multiprotocol Extensions for BGP-4) also states that the Next Hop must be a routable global address.

Therefore:

C. It must be a global unicast address — is correct.

The other options involving link-local addresses are incorrect.

Congestion Avoidance in Networking

Congestion avoidance mechanisms prevent packet loss and delay by managing queues before congestion occurs.

Common Congestion Avoidance Techniques:

Weighted Random Early Detection (WRED) – Randomly drops low-priority packets before congestion builds up.

Explicit Congestion Notification (ECN) – Marks packets instead of dropping them to signal congestion.

Queue Management – Techniques like priority queuing (PQ) and weighted fair queuing (WFQ) help prevent congestion.

Reference from Huawei HCIE-Datacom Documentation:

Huawei QoS Configuration Guide – Congestion Avoidance Technologies

HCIE-Datacom Study Material – Traffic Management and Queue Optimization

The default port for iMaster NCE-Campus northbound RESTful APIs is 18006. This port is used by external platforms and applications to interact with iMaster NCE via its open API interface.

Exact Extract - Huawei iMaster NCE-Campus API Integration Guide:

“Northbound interfaces of iMaster NCE-Campus are accessible via port 18006 by default. This allows external systems to use open APIs for automation and integration.”

Comprehensive and Detailed In-Depth Explanation:

When IS-IS is used as the IGP (Interior Gateway Protocol) to advertise Segment Routing (SR) SIDs, the Level-2 (L2) router advertises node SIDs globally across the entire IS-IS domain, not just within a single area.

Level-1 (L1) routers only advertise within the local area, but L2 routers distribute information across multiple areas, enabling inter-area reachability.

Therefore, the statement is FALSE.