Huawei H12-891_V1.0 問題集

質問 1：

Refer to the configuration in the figure. Which queue on R2 do packets of PC1 enter by default?
A. AF4
B. AF2
C. AF3
D. EF
正解：C
解説: (Topexam メンバーにのみ表示されます)

質問 2：
In a VXLAN scenario, which of the following features can be enabled to reduce ARP packet flooding between VTEPs?
A. Host information collection
B. Local proxy ARP
C. Port isolation
D. ARP broadcast suppression
正解：A,B,D
解説: (Topexam メンバーにのみ表示されます)

質問 3：
In the firewall hot standby scenario, which of the following status information can be backed up between the active and standby firewalls?
A. Session table
B. AAA user table (excluding the default user admin)
C. Server mapping table
D. Dynamic MAC address table
正解：A,B,C
解説: (Topexam メンバーにのみ表示されます)

質問 4：
Which of the following is the drop probability of packets exceeding the upper threshold in WRED?
A. 0.5
B. 0.2
C. 1
D. 0.8
正解：C
解説: (Topexam メンバーにのみ表示されます)

質問 5：
On a campus network, iMaster NCE-Campus is used to deploy two VNs (Virtual Networks): R&D VN and Marketing VN. Users in these two VNs belong to two separate security groups.
The campus network requires R&D personnel and sales personnel to communicate with each other. To meet this requirement, which of the following tasks does a network administrator need to perform?
A. Deploy a policy control matrix.
B. Deploy an external network.
C. Deploy network service resources.
D. Configure inter-VN communication.
正解：A,D
解説: (Topexam メンバーにのみ表示されます)

質問 6：
During the evolution from OSPFv2 to OSPFv3, LSA formats and functions remain unchanged, except that the network layer addresses in LSAs are changed from IPv4 to IPv6.
A. FALSE
B. TRUE
正解：A
解説: (Topexam メンバーにのみ表示されます)

質問 7：
Which of the following statements about BIER (Bit Index Explicit Replication) and PIM (Protocol Independent Multicast) are correct?
A. On a BIER-based multicast network, multicast users must send group join messages hop by hop.
B. On a PIM-based multicast network, an MDT covering all nodes that multicast traffic traverses needs to be established.
C. On a BIER-based multicast network, an MDT covering all nodes that multicast traffic traverses does not need to be established.
D. On a BIER-based multicast network, packets sent by the multicast source must be encapsulated with the Bitstring field.
正解：B,C,D
解説: (Topexam メンバーにのみ表示されます)

質問 8：
The ingress VTEP performs both Layer 2 and Layer 3 table lookup for packet forwarding. The forwarding mode is _____ IRB forwarding. (Capitalize the first letter.)
正解：
Symmetric
Explanation:
Understanding IRB (Integrated Routing and Bridging) Forwarding in VXLAN VXLAN (Virtual Extensible LAN) supports Layer 2 and Layer 3 forwarding between Virtual Network Identifiers (VNIs).
* IRB (Integrated Routing and Bridging) enables inter-subnet communication within a VXLAN fabric.
* There are two modes of IRB forwarding:
* Symmetric IRB
* Asymmetric IRB
Why the Answer is "Symmetric" IRB Forwarding?
# Ingress VTEP performs both Layer 2 and Layer 3 lookups:
* Symmetric IRB requires both ingress and egress VTEPs to perform Layer 3 lookups.
* The ingress VTEP (source gateway) performs a Layer 2 MAC lookup, then a Layer 3 lookup to find the destination VTEP.
* The egress VTEP (destination gateway) performs another Layer 3 lookup before forwarding the packet to the destination.
# Asymmetric IRB does not perform two lookups at the ingress VTEP:
* In Asymmetric IRB, the ingress VTEP performs both Layer 2 and Layer 3 forwarding and sends a Layer 2 packet to the egress VTEP.
* The egress VTEP only does a Layer 2 lookup, not a Layer 3 lookup.
* Since the question states that both L2 and L3 lookups occur at the ingress VTEP, asymmetric IRB is incorrect.
# Why Symmetric IRB is More Common?
* Scalability: Supports any-to-any communication across VXLAN networks.
* More Efficient Routing: Uses Layer 3 VXLAN encapsulation, ensuring efficient routing between VNIs.
# Reference: Huawei HCIE Datacom - VXLAN Symmetric and Asymmetric IRB Forwarding