Free Access to Huawei.H12-891_V1.0.v2026-06-05.q295 with Valid Practice Test (Page 46)

Question 221

As shown in the figure, SW1 and SW2 use asymmetric IRB (Integrated Routing and Bridging) forwarding, and PC1 and PC2 communicate with each other. Which of the following is the destination MAC address of the original data frame in the packet sent from VTEP1 to VTEP2?

A.MAC D
B.MAC B
C.MAC C
D.MAC A

Correct Answer: C

Comprehensive and Detailed In-Depth
1. Understanding VXLAN Asymmetric IRB Forwarding:
In VXLAN (Virtual Extensible LAN) networks, there are two types of IRB forwarding: Symmetric IRB and Asymmetric IRB.
In Asymmetric IRB, routing occurs only at the ingress VTEP (Virtual Tunnel Endpoint).
The ingress VTEP (VTEP1) encapsulates the original data frame and sends it to the egress VTEP (VTEP2) over the VXLAN tunnel.
The destination MAC address of the original Ethernet frame is the MAC address of the Layer 3 gateway (VBDIF) at the egress VTEP.
2. Analyzing the Topology:
PC1 (172.16.2.1/24) with MAC A is sending traffic to PC2 (172.16.1.2/24) with MAC D.
Both PCs are in different subnets, so inter-subnet routing is required.
VTEP1 (1.1.1.1) on SW1 is the ingress VTEP.
VTEP2 (2.2.2.2) on SW2 is the egress VTEP.
The VXLAN Network Identifier (VNI) for the traffic is 100.
SW1 has two VBDIF interfaces:
VBDIF10 (MAC B) - Interface for BD10 (172.16.2.254).
VBDIF20 (MAC C) - Interface for BD20 (172.16.1.254).
3. Packet Flow in Asymmetric IRB:
Step 1: PC1 sends a packet destined for PC2. The packet is routed at the ingress VTEP (SW1) using the VBDIF interface (VBDIF10 with MAC B).
Step 2: The ingress VTEP (SW1) encapsulates the packet in a VXLAN header (VNI 100) and sends it to VTEP2.
Step 3: The original data frame inside the VXLAN packet must have a destination MAC address that matches the gateway MAC address (VBDIF20 - MAC C) at the egress VTEP (SW2).
Step 4: On reaching VTEP2, the encapsulation is removed, and the original frame with destination MAC C is forwarded.
Step 5: VTEP2 performs Layer 3 routing to forward the packet to PC2.
4. Why MAC C is Correct:
In asymmetric IRB forwarding, the routing decision at the ingress VTEP ensures that the destination MAC in the original frame is set to the VBDIF (gateway) MAC of the egress VTEP.
Since the egress VTEP (SW2) has VBDIF20 (MAC C) for the destination subnet (172.16.1.0/24), the destination MAC address of the original frame is MAC C.
Reference:
Huawei HCIE-Datacom V1.0 Training Materials
Huawei Official Documentation: VXLAN Configuration Guide
VXLAN Asymmetric IRB Forwarding Concept
HCIE-Datacom Knowledge Base: VXLAN and IRB Configurations

Question 222

A carrier's home broadband service requires a maximum downstream bandwidth of 100 Mbit/s during off- peak hours and a guaranteed downstream bandwidth of 50 Mbit/s during peak hours. The home broadband service includes the home IP phone service and the home Internet access service. Which of the following configurations best meets the service requirement?

A.qos gts cir 100000
B.qos car inbound cir 50000 pir 100000
C.qos car inbound cir 100000 pir 50000
D.qos car inbound cir 100000

Question 223

BFD can implement millisecond-level link status detection.

A.TRUE
B.FALSE

Question 224

On a CloudCampus virtualized campus network, service data enters different VNs from physical networks through edge nodes, and the VN that the data will enter is determined by the VLANs to which users belong. Which of the following statements about dynamic VLAN authorization is incorrect?

A.When wired users pass 802.1X authentication, they join the authorization VLANs delivered to edge nodes.
B.When wireless users pass Portal authentication, they join the authorization VLANs delivered to edge nodes.
C.When wireless users pass 802.1X authentication, they join the authorization VLANs delivered to edge nodes.
D.When wired users pass MAC address authentication, they join the authorization VLANs delivered to edge nodes.

Question 225

The advantages of building a campus network using stacking, clustering technology include which of the following?( Multi-select)

A.Improved network equipment and link utilization
B.It can effectively reduce network power consumption
C.Simplifies network management and reduces the complexity of network deployment planning
D.Business disruption time is greatly reduced

Question 221

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