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Question 450 of 497

Implementing hybrid interconnectivity →easyMultiple ChoiceObjective-mapped

Quick Answer

The answer is that the 'encryption: IPSEC' field indicates traffic over this VLAN attachment is encrypted using IPsec. This is correct because Google Cloud’s Dedicated Interconnect allows you to enable IPsec encryption directly on the VLAN attachment itself, providing confidentiality and integrity for data in transit without needing a separate Cloud VPN tunnel. On the Google Professional Cloud Network Engineer exam, this tests your understanding of how Dedicated Interconnect can be secured at the attachment level, often appearing in scenario-based questions where you must differentiate between native IPsec on the VLAN and a separate VPN tunnel. A common trap is assuming IPsec encryption requires an additional VPN gateway, but the key insight is that the VLAN attachment itself handles encryption when this field is present. Memory tip: think “attachment-level armor” — if you see ‘encryption: IPSEC’ on the VLAN, the encryption is built into the interconnect, not bolted on later.

PCNE Implementing hybrid interconnectivity Practice Question

This PCNE practice question tests your understanding of implementing hybrid interconnectivity. Read the scenario carefully and evaluate each option against the stated constraints before committing to an answer. After answering, compare your reasoning against the explanation and wrong-answer breakdown below. Once you have made your selection, read the full explanation to reinforce the concept and understand why each distractor is designed to mislead on exam day.

Exhibit

Refer to the exhibit.

```
$ gcloud compute interconnects attachments describe my-attachment --region=us-central1
binding: 0
cloudRouterIpAddress: 169.254.1.1/29
customerRouterIpAddress: 169.254.1.2/29
dataplaneVersion: 2
encryption: IPSEC
interconnect: my-interconnect
privateInterconnectInfo:
  tag8021q: 100
state: ACTIVE
type: DEDICATED
vlanTag8021q: 100
```

A network engineer is setting up Dedicated Interconnect and sees the output above. What does the 'encryption: IPSEC' field indicate about this VLAN attachment?

Question 1easymultiple choice

Open the full VLAN trunking answer →

Exhibit

Refer to the exhibit.

```
$ gcloud compute interconnects attachments describe my-attachment --region=us-central1
binding: 0
cloudRouterIpAddress: 169.254.1.1/29
customerRouterIpAddress: 169.254.1.2/29
dataplaneVersion: 2
encryption: IPSEC
interconnect: my-interconnect
privateInterconnectInfo:
  tag8021q: 100
state: ACTIVE
type: DEDICATED
vlanTag8021q: 100
```

A
Traffic over this VLAN attachment is encrypted using IPsec
IPsec encryption is enabled on this attachment.
B
The attachment is using Cloud VPN as the underlying transport
Why wrong: The attachment is on a Dedicated Interconnect, not Cloud VPN.
C
The attachment requires a Cloud VPN tunnel in addition to the Interconnect
Why wrong: IPsec is integrated into the attachment itself; no separate VPN is needed.
D
The attachment is using MACsec encryption at layer 2
Why wrong: The field shows IPSEC, not MACsec.

Full breakdown with real-world context →

Answer choices

Why each option matters

Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.

Correct answer & explanation

✓

Traffic over this VLAN attachment is encrypted using IPsec

The 'encryption: IPSEC' field in the VLAN attachment output for Dedicated Interconnect indicates that traffic traversing this attachment is encrypted using IPsec. This is a feature of Google Cloud's Dedicated Interconnect that allows you to enable IPsec encryption on the VLAN attachment itself, providing confidentiality and integrity for data in transit without requiring a separate Cloud VPN tunnel.

Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

✓
Traffic over this VLAN attachment is encrypted using IPsec
Why this is correct
IPsec encryption is enabled on this attachment.
Related concept
Read the scenario before looking for a memorised answer.
✗
The attachment is using Cloud VPN as the underlying transport
Why it's wrong here
The attachment is on a Dedicated Interconnect, not Cloud VPN.
✗
The attachment requires a Cloud VPN tunnel in addition to the Interconnect
Why it's wrong here
IPsec is integrated into the attachment itself; no separate VPN is needed.
✗
The attachment is using MACsec encryption at layer 2
Why it's wrong here
The field shows IPSEC, not MACsec.

Common exam traps

Common exam trap: answer the scenario, not the keyword

Google Cloud often tests the misconception that IPsec encryption on a VLAN attachment requires a separate Cloud VPN tunnel, but in reality, the encryption is a built-in feature of the attachment itself.

Trap categories for this question

Command / output trap
The field shows IPSEC, not MACsec.

Detailed technical explanation

How to think about this question

IPsec encryption on a Dedicated Interconnect VLAN attachment uses Encapsulating Security Payload (ESP) in tunnel mode to encrypt the entire IP packet, with the encryption keys managed by Google Cloud's Cloud Router. This setup allows you to meet compliance requirements for encrypted traffic over a private connection without the overhead of a separate VPN gateway, and it supports IKEv2 for key exchange. A real-world scenario is a financial institution that needs end-to-end encryption for sensitive data but wants the low latency and high bandwidth of a direct interconnect.

KKey Concepts to Remember

Read the scenario before looking for a memorised answer.
Find the constraint that changes the correct option.
Eliminate answers that are true in general but not in this case.

TExam Day Tips

Watch for words such as best, first, most likely and least administrative effort.
Review why wrong options are wrong, not only why the correct option is correct.

Key takeaway

Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.

Real-world example

How this comes up in practice

A healthcare organisation deploys an application with a public-facing web tier and a private database tier. The database subnet has no public IP and only accepts connections from the web tier's security group. Questions like this test whether you can design cloud network isolation using VNets/VPCs, subnets, and security group rules.

What to study next

Got this wrong? Here's your next step.

Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.

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FAQ

Questions learners often ask

What does this PCNE question test?

Implementing hybrid interconnectivity — This question tests Implementing hybrid interconnectivity — Read the scenario before looking for a memorised answer..

What is the correct answer to this question?

The correct answer is: Traffic over this VLAN attachment is encrypted using IPsec — The 'encryption: IPSEC' field in the VLAN attachment output for Dedicated Interconnect indicates that traffic traversing this attachment is encrypted using IPsec. This is a feature of Google Cloud's Dedicated Interconnect that allows you to enable IPsec encryption on the VLAN attachment itself, providing confidentiality and integrity for data in transit without requiring a separate Cloud VPN tunnel.

What should I do if I get this PCNE question wrong?

Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.

What is the key concept behind this question?

Read the scenario before looking for a memorised answer.

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Last reviewed: Jun 30, 2026

Question Discussion

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This PCNE practice question is part of Courseiva's free Google Cloud certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the PCNE exam.