ISC2 CC Network Security Practice Question
A financial services firm wants to allow employees to securely access internal applications from home without exposing those applications directly to the internet. The security team proposes using a VPN that encrypts traffic at the network layer and can carry non-web protocols. Which VPN technology best meets this requirement?
⚠ Common exam trap
The trap here is assuming any encrypted remote access method, such as a TLS web portal or SSH tunnel, provides the same broad network-layer VPN coverage as IPsec tunnel mode.
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
✓
IPsec in tunnel mode
IPsec in tunnel mode encrypts and encapsulates entire IP packets, enabling remote users to securely reach internal applications over any IP-based protocol. Unlike browser-based TLS VPNs or SSH port forwarding, it provides transparent network-layer connectivity without exposing applications to the internet. RADIUS with 802.1X handles LAN access control, not remote traffic encryption, so it cannot meet the stated requirement.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
TLS-based web VPN portal
Why it's wrong here
A TLS-based web VPN portal typically provides browser-based access to specific web applications through a reverse proxy, not full network-layer connectivity. It cannot natively carry arbitrary non-web protocols such as SMB or RDP without additional plugins, so it would not satisfy the requirement to securely reach all internal applications over non-web protocols.
- ✗
RADIUS authentication with 802.1X
Why it's wrong here
RADIUS with 802.1X is used for network access control on LANs and wireless, authenticating devices before granting network access. It does not encrypt traffic between a remote employee and internal applications, nor does it tunnel non-web protocols. Therefore, it fails to provide the secure remote access VPN capability the firm requires.
- ✓
IPsec in tunnel mode
Why this is correct
IPsec in tunnel mode encapsulates entire IP packets, encrypting the payload and original headers, so remote clients can reach internal applications over any IP-based protocol. It operates at the network layer, providing confidentiality and integrity for non-web traffic, which matches the firm's need to avoid exposing applications directly while supporting diverse internal services.
- ✗
SSH port forwarding
Why it's wrong here
SSH port forwarding can tunnel specific TCP ports, but it requires per-application configuration and user knowledge of SSH commands. It does not provide a transparent network-layer VPN that routes all IP traffic to internal applications, making it unsuitable for broad, secure access by employees to multiple internal services from home.
Quick reference
AAA Protocol Comparison
| Protocol | Port(s) | Encryption | Transport | Primary Use |
|---|---|---|---|---|
| RADIUS | 1812 / 1813 | Password only | UDP | Network access control |
| TACACS+ | 49 | Full packet | TCP | Device administration |
| Diameter | 3868 | Full session | TCP / SCTP | Carrier / mobile networks |
| 802.1X | — | EAP-based | Layer 2 | Port-based access control |
TACACS+ encrypts the entire packet; RADIUS only encrypts the password field — a key exam distinction.
Go deeper
Related to this question
Learn chapter
Access Control Fundamentals
Key term
Hypertext Transfer Protocol Secure
Hypertext Transfer Protocol Secure, or HTTPS, is the secure version of HTTP that encrypts data between a web browser and a website using SSL/TLS to protect sensitive information like passwords and credit card numbers.
Key term
VPN
A VPN creates an encrypted tunnel over a public network to securely connect remote users or sites to a private network.
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This CC question is part of Courseiva's 989-question bank — original exam-style content with full explanations and wrong-answer analysis, never real exam questions or exam dumps. Learn why practice questions differ from exam dumps →
JA
Written and reviewed by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
Last reviewed September 2026 · checked against the official ISC2 exam blueprint
This CC practice question is part of Courseiva's free ISC2 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 CC exam.