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

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.

Comprehensive and Detailed In-Depth Explanation:

Understanding the OSPF Network Structure in the Question:

OSPF Areas & Routers:

Area 3: Contains R5 (which has loopback 10.0.5.5/32).

Area 1: Contains R6.

Area 2: Contains R4.

Area 0 (Backbone Area): Contains R1, R2, and R3 (which interconnect the other areas).

ACL 2000 Filtering Rule:

The ACL rule 2000 explicitly denies 10.0.5.5/32 from being imported.

The filter 2000 import command applies this filter to Area 0, preventing routes from Area 3 (including R5's loopback) from being learned by Area 0 routers (R1, R2, and R3).

Route Distribution Analysis:

R5 (Area 3):

R5 has 10.0.5.5/32 configured on its Loopback0.

Since OSPF is enabled, R5 advertises the route to R6 in Area 1.

R6 (Area 1) → R2 (Area 0, Backbone Router):

Without filtering, R6 would normally propagate 10.0.5.5/32 to R2 (since R2 is a backbone router in Area 0).

However, since ACL 2000 is applied in Area 0, R2 blocks this route from being imported.

Therefore, R2 does not learn 10.0.5.5/32.

R2 → R1 and R3 (Both in Area 0):

R2 would typically share any learned routes with R1 and R3 in Area 0.

But since R2 itself does not have 10.0.5.5/32, neither R1 nor R3 can receive it.

Thus, R1 and R3 also do not have 10.0.5.5/32 in their routing tables.

R4 (Area 2) is Unaffected:

Since R4 is in Area 2, it is not directly impacted by the filter applied in Area 0.

It can still receive the route via another path if redistribution is configured properly.

Final Conclusion:

R1, R2, and R3 do not have the 10.0.5.5/32 route due to the filter 2000 import command applied in Area 0.

R4 may still have the route since it is not affected by the filtering in Area 0.

Thus, the correct answer is:✅ R1, R3, R2 do not have the route 10.0.5.5/32 in their routing tables.