H12-831_V1.0 Exam Dumps : HCIP-Datacom-Advanced Routing & Switching Technology V1.0

Comprehensive and Detailed In-Depth Explanation:

To verify the correct answer, we need to analyze Bidirectional Forwarding Detection (BFD) behavior and the provided configuration.

1. Understanding BFD Configuration Parameters

BFD (Bidirectional Forwarding Detection) is a protocol used for fast failure detection between directly connected devices.

Key Configuration Parameters in BFD:

Peer IP (bind peer-ip)

This specifies the destination router’s IP address for the BFD session.

✅ Correctly configured on both R1 and R2.

Discriminator Local/Remote (discriminator local X / remote Y)

These values must match between the two routers.

✅ Correctly configured (R1: local 1, remote 2; R2: local 2, remote 1).

Min-TX Interval (min-tx-interval)

Defines the minimum transmit interval for BFD packets.

❌ Missing from R2’s configuration (could be a cause for mismatch).

Min-RX Interval (min-rx-interval)

Defines the minimum receive interval for BFD packets.

❌ Missing from R2’s configuration (could be a cause for mismatch).

2. Analyzing the Configuration on R1 and R2

✅ Configuration on R1 (Correct)

shell

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bfd tor2 bind peer-ip 10.0.12.2

discriminator local 1

discriminator remote 2

min-tx-interval 1500

min-rx-interval 1500

This configuration is correct.

❌ Configuration on R2 (Incomplete)

shell

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bfd tor1 bind peer-ip 10.0.12.1

discriminator local 2

discriminator remote 1

Missing min-tx-interval and min-rx-interval.

3. Why the Answer is FALSE?

A BFD session does NOT go down due to mismatched timing parameters.

BFD dynamically negotiates timing values, meaning even if R2 is missing min-tx/min-rx values, the session should still establish.

However, the session will fail if the peer IP or discriminator values are incorrect (which they are NOT in this case).

The actual cause of failure in this case is likely the missing min-tx and min-rx settings on R2, NOT a mismatch between R1 and R2.

Comprehensive and Detailed In-Depth Explanation:

Understanding the DHCP Process in This Scenario:

DHCP Server on R2:

The DHCP server is configured on interface GE0/0/0 of R2.

The address pool is an interface address pool, meaning that IP addresses are allocated from the subnet of GE0/0/0 (i.e., 10.0.12.0/24).

DHCP Clients on R1:

Both interfaces (GE0/0/0 and GE0/0/1) on R1 are set as DHCP clients, meaning they will send DHCP DISCOVER messages to obtain an IP address dynamically.

Why Only One Interface Gets an IP Address?

Interface address pools in Huawei devices assign only one IP address per MAC address (which is typically the router’s MAC).

Since both interfaces belong to R1, they share the same MAC address when making a DHCP request.

As a result, the DHCP server on R2 only assigns one IP address to the first requesting interface.

The second request is ignored or denied by the DHCP server due to the duplicate MAC address issue.

Key Takeaways:

Huawei routers using an interface-based DHCP address pool assign only one IP per MAC address.

Since both interfaces on R1 have the same MAC, only one gets an IP.

This behavior is expected in Huawei’s HCIP-Datacom-certified DHCP configurations.

HCIP-Datacom-Advanced Routing & Switching Technology References:

Huawei HCIP-Datacom Official Certification Guide, Chapter on DHCP Server and Client Configurations.

Huawei Datacom Configuration Guide, Section on Interface Address Pools and Address Assignment Limitations.

Huawei Enterprise Networking Training Materials, DHCP Relay and DHCP Server Behavior.