Huawei Updated H12-821_V1.0 Exam Questions and Answers by lucie

 Silent Interface Explanation

Thesilent-interfacecommand is used to prevent OSPF from sending or receiving OSPF packets on the specified interface (GE 0/0/1). This disables OSPF adjacency establishment and stops route advertisement for that interface.

 Network Observations

Statement A: R2 can access the server.This is correct, as the silent interface does not impact data traffic, only OSPF-related communication.

Statement B: GE 0/0/1 of R1 cannot send OSPF packets.Correct due to thesilent-interfaceconfiguration.

Statement C: The network segment to which GE 0/0/1 of R1 belongs cannot be advertised.This is correct, as the silent interface prevents route advertisement.

Statement D: GE 0/0/1 of R1 cannot accept OSPF packets.Correct, as the silent interface configuration blocks packet reception.

 HCIP-Datacom-Core Reference

OSPF interface command behavior is outlined in the configuration and lab examples sections​​.

Understanding DHCPv6:

DHCPv6 (Dynamic Host Configuration Protocol for IPv6) is used to assign configuration parameters to IPv6 clients.

It supports bothstatefulandstatelessmodes:

Stateful: Assigns IPv6 addresses and other configuration parameters.

Stateless: Assigns only configuration parameters (e.g., DNS server) without providing IPv6 addresses.

HCIP-Datacom-Core Technology Training Material (IPv6 Address Configuration and DHCPv6)​​.

Analysis of Parameters:

A. Gateway address:

False. DHCPv6 does not assign the default gateway. Instead, the default gateway is advertised by routers usingRouter Advertisement (RA)messages in IPv6.

B. DNS server address:

True. DHCPv6 can assign the IPv6 address of DNS servers to the client.

C. IPv6 address/prefix:

True. In stateful mode, DHCPv6 assigns IPv6 addresses and prefixes to clients.

D. SNTP server address:

True. DHCPv6 can assign the address of an SNTP (Simple Network Time Protocol) server to synchronize time on the client.

An IP prefix filter is designed to match both the IP address and its prefix length, making it suitable for filtering routing information rather than data packets. Options A and D are incorrect because IP prefix filters do not work directly on data packets, and they can match both prefix numbers and lengths ​.

Comprehensive and Detailed Step-by-Step Explanation:

1. Overview of BFD Optimization:

BFD (Bidirectional Forwarding Detection) is a protocol that provides rapid detection of link failures.

Optimizing BFD involves adjusting parameters to balance between detection speed and network stability.

2. Analysis of Each Statement:

Option A: After a high priority is configured for BFD packets, BFD packets are preferentially forwarded.

Correct (True Statement).

High priority ensures that BFD packets are not delayed or dropped under congestion, improving detection accuracy.

Option B: To quickly learn about the network status and performance requirements, you can set the interval for sending BFD packets to the minimum value.

Incorrect (False Statement).

Setting the interval to the minimum value can lead to excessive BFD session flapping, which may overload the network or cause instability. The interval should be configured based on network requirements and conditions, rather than set to the minimum.

Option C: On a live network, some devices switch traffic only when a BFD session changes to the Up state... configure a delay to compensate for the time difference.

Correct (True Statement).

This is a valid optimization to avoid issues caused by timing mismatches between BFD and routing protocols.

Option D: If a BFD session flaps, master/backup switchovers are frequently performed... set the WTR time.

Correct (True Statement).

The WTR (Wait to Restore) timer helps stabilize BFD by delaying session recovery after a flap, reducing the risk of frequent switchovers.

3. Summary:

The false statement isB, as setting the BFD packet interval to the minimum can destabilize the network.