H12-821_V1.0 Exam Dumps - Huawei HCIP-Datacom Questions and Answers

 IGMP: Manages IPv4 multicast group members and runs on the multicast network ' s last segment (that is, the network segment where a Layer 3 network device is connected to user hosts).

 PIM: Sends multicast data over the network to the multicast device that is connected to group members that have requested the multicast data, implementing multicast data forwarding based on routes.

 IGMP Snooping: Manages and controls the forwarding of multicast data packets to effectively suppress the flooding of multicast data packets on the Layer 2 network.

 IGMP (Internet Group Management Protocol) :

IGMP is used by hosts and adjacent multicast routers to establish and maintain multicast group memberships on a local subnet.

It allows a host to inform a multicast router of its desire to receive multicast traffic for a specific group.

It operates at Layer 3 and runs on the last segment of the network.

Attributes such as community , tag , and origin can be directly referenced in the apply clause of a route-policy. However, IP-prefix is not an attribute but a prefix list used for matching, and it cannot be directly applied ​.

Comprehensive and Detailed Step-by-Step Explanation:

1. Features of Wi-Fi 6:

Wi-Fi 6 (802.11ax) introduces several new technologies to improve network efficiency, reduce latency, and optimize power usage:

OFDMA (Orthogonal Frequency Division Multiple Access): Allows multiple devices to transmit simultaneously, improving concurrency.

TWT (Target Wake Time): Reduces power consumption by scheduling communication times for devices.

High Bandwidth: Supports up to 9.6 Gbps, significantly faster than Wi-Fi 5.

2. Why Zero Latency is Incorrect:

While Wi-Fi 6 reduces latency compared to earlier standards, zero latency is not achievable due to inherent delays in network communication.

The statement " Realizes zero latency " is misleading and technically inaccurate.

3. Analysis of Each Option:

Option A: Uses OFDMA technology to achieve high concurrency.

Correct (True Statement).

OFDMA is a core feature of Wi-Fi 6 that improves concurrent communication.

Option B: Realizes zero latency, ensuring efficient service running.

Incorrect (False Statement).

Wi-Fi 6 reduces latency but cannot eliminate it entirely.

Option C: Provides high bandwidth, up to 9.6 Gbps.

Correct (True Statement).

Wi-Fi 6 supports a theoretical maximum bandwidth of 9.6 Gbps.

Option D: Uses TWT technology to reduce terminal power consumption.

Correct (True Statement).

TWT schedules communication times, allowing devices to enter low-power states and conserve battery life.

4. Summary:

The false statement is B , as Wi-Fi 6 does not achieve zero latency.

Comprehensive and Detailed in-depth Step-by-Step Explanation:

BGP (Border Gateway Protocol) uses specific message types to establish and maintain peer relationships between routers. The primary BGP messages involved during the establishment and maintenance of peer relationships are:

Open (D):

The Open message is the first message sent after a TCP connection is established between BGP peers.

It is used to exchange parameters such as the AS number, BGP version, hold time, and BGP identifier.

Keepalive (A):

After the Open message exchange, Keepalive messages are sent periodically to maintain the BGP session.

These messages confirm that the connection is still alive.

Update (C):

Update messages are used to exchange routing information after the peer relationship is established.

They contain information about network prefixes and their associated path attributes.

Hello (B):

Hello messages are not used in BGP. They are typically used in protocols like OSPF or IS-IS to establish and maintain neighbor relationships.

Thus, the correct answers are A (Keepalive) , C (Update) , and D (Open) .

Comprehensive and Detailed In-Depth Explanation:

AS_Path is a well-known mandatory attribute (not discretionary).

AS_Path characteristics :

A. TRUE → When advertising to IBGP peers, AS_Path remains unchanged to prevent routing loops.

B. TRUE → BGP uses AS_Path to detect loops (if a router sees its own AS in the path, it rejects the route).

C. FALSE → AS_Path is well-known mandatory, not discretionary .

D. TRUE → BGP ignores AS_Confed_Sequence and AS_Confed_Set when calculating the AS_Path length.

???? Reference: Huawei HCIA-Datacom Study Guide, BGP Path Attributes and Loop Prevention.

The route-policy configuration specifies that node 10 matches the IP prefix 11.1.0.0/16 and applies a cost of 300 to this route. Once a route matches a node, it is no longer processed by subsequent nodes, making option D incorrect. Option B is also incorrect because only specific matching routes have their costs changed ​.

The output shows that the router with the IP 10.0.12.2 is the Backup Designated Router (BDR), as indicated in the State: BDR field. The router ID is 10.0.2.2 , the interface cost is 1, and the IP address of the interface is 10.0.12.2 . Hence, C is the correct answer ​.