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

Comprehensive and Detailed In-Depth Explanation:

Understanding the BGP Network Topology in the Question:

EBGP Peering

Each router forms EBGP peer relationships with directly connected neighbors.

This is a fully meshed topology, meaning each router exchanges BGP routes with its adjacent routers.

Routing Information for 192.168.1.0/24

R1 and R4 import the static route 192.168.1.0/24 into BGP.

Since BGP prefers the shortest AS path, traffic to 192.168.1.0/24 will follow the shortest path to R1 or R4.

Route Analysis for Each Statement:

Statement A: R6 → R5 → R4 ✅ (Correct)

R6 does not have a direct route to 192.168.1.0/24, so it must rely on BGP advertisements from its EBGP neighbors.

R5 learns the route to 192.168.1.0/24 from R4.

Therefore, R6 forwards traffic to R5, and then R5 sends it to R4.

✅ Correct path: R6 → R5 → R4

Statement B: R5 → R4 ✅ (Correct)

R5 is directly connected to R4, and since R4 advertises the 192.168.1.0/24 route via BGP,

R5 will forward traffic directly to R4 as the shortest AS path.

✅ Correct path: R5 → R4

Statement C: R2 → R1 ✅ (Correct)

R2 is directly connected to R1 and learns the 192.168.1.0/24 route from R1 via BGP.

Since R1 advertises the static route, R2 forwards traffic directly to R1.

✅ Correct path: R2 → R1

Statement D: R3 → R2 → R1 ✅ (Correct)

R3 is directly connected to R2 and learns the 192.168.1.0/24 route from R2 via BGP.

Since R2 prefers R1 as the shortest AS path to 192.168.1.0/24,

R3 will send traffic to R2, and R2 will send it to R1.

✅ Correct path: R3 → R2 → R1

Final Conclusion:

✅ A. The path for traffic from R6 to 192.168.1.0/24 is R6 → R5 → R4.

✅ B. The path for traffic from R5 to 192.168.1.0/24 is R5 → R4.

✅ C. The path for traffic from R2 to 192.168.1.0/24 is R2 → R1.

✅ D. The path for traffic from R3 to 192.168.1.0/24 is R3 → R2 → R1.

Thus, the correct answers are: A, B, C, D.

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.

OSPFv3 introduces Link-LSAs to advertise link-local addresses, IPv6 prefixes, and relevant interface options to routers connected to the same link.

Unlike Router-LSAs and Network-LSAs, a Link-LSA provides IPv6 addressing information associated with a particular interface.

In the displayed Link-LSA, the field Number of Prefixes has a value of 3. Three IPv6 prefix entries are listed: 2000:14::/64, 2001:14::/64, and 2002:14::/64.

The exhibit also includes a link-local IPv6 address beginning with FE80::. This address belongs to the link-local address space and must not be counted as a global unicast prefix.

Therefore, the intended examination interpretation is that the interface has three global unicast address prefixes.

Strictly, an LSA ' s prefix count does not independently prove the precise number of individual interface addresses, but among the provided options, D is the intended answer.