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

Comprehensive and Detailed In-Depth Explanation:

1. Understanding the Network Setup

PE1 (Provider Edge 1) is the gateway for network 192.168.1.1/24.

PE2 (Provider Edge 2) is the gateway for network 192.168.2.1/24.

A cloud-based backbone connects PE1 and PE2.

To verify end-to-end communication, engineers need to check reachability between PE1 and PE2.

2. Evaluating Each Answer Option

Option A: "Configuring NQA on PE1 and PE2, with the destination address being the IP address of each other."

✅ Correct.

NQA (Network Quality Analysis) is a network testing tool that allows connectivity testing between two devices.

Configuring NQA between PE1 and PE2 will verify end-to-end reachability.

Option B: "On PE1 and PE2, checking whether the ARP table contains the ARP entry of the peer network segment."

❌ Incorrect.

ARP (Address Resolution Protocol) is only used for resolving MAC addresses within the same broadcast domain.

Since PE1 and PE2 are in different network segments (separated by a routed network), they will not have ARP entries for each other.

Instead, routing entries should be checked, not ARP.

Option C: "On PE1, using 192.168.1.1 as the source address to ping 192.168.2.1."

✅ Correct.

A simple ping test using the source address of PE1 (192.168.1.1) to reach PE2 (192.168.2.1) will verify whether routing between the two locations is functional.

Option D: "On PE1 and PE2, checking whether there are routes to each other’s network segment in the routing tables."

✅ Correct.

If routing is not configured correctly, PE1 and PE2 will not know how to reach each other.

Checking the routing table ensures that both PEs have the correct next-hop information.

Final Answer:

✅ A, C, and D are correct.

HCIP-Datacom-Advanced Routing & Switching Technology References:

Using NQA for Network Connectivity Testing

Verifying Routing Table Entries for Inter-Network Communication

Understanding ARP and Its Limitations in Routed Networks

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

CopyEdit

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

CopyEdit

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.