PEN-200 Port Redirection and Tunneling Practice Question
During an internal penetration test, you gain shell access to a Linux machine. You want to pivot deeper into a segmented internal network that is completely unreachable directly from your attack host. Which tunneling approach establishes a true layer 2 network tunnel by creating a virtual network interface, allowing you to route raw Ethernet frames and perform ARP scanning?
⚠ Common exam trap
Many candidates confuse Layer 2 TAP interfaces with Layer 3 TUN interfaces or simple SSH port forwarding. Remember that port forwarding only handles TCP or UDP streams, whereas Layer 2 tunneling allows raw framing and ARP scanning across boundaries.
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
✓
Setting up a TAP network interface tunnel
Creating a TUN or TAP device using tools like sshuttle or OpenVPN establishes a Layer 3 or Layer 2 tunnel respectively. A TAP interface operates at Layer 2, allowing raw Ethernet frames to cross the boundary. This capability is essential when standard TCP/UDP port forwarding fails because you need to execute broadcast-dependent reconnaissance or vulnerability scanning against hidden internal subnets.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Local port forwarding using SSH (-L flag)
Why it's wrong here
Local port forwarding binds a specific local port to a remote destination through an SSH tunnel. It only handles TCP streams for designated ports and cannot route arbitrary packets, perform ARP scans, or handle non-TCP protocols across the network boundary.
- ✗
Remote port forwarding using SSH (-R flag)
Why it's wrong here
Remote port forwarding exposes a port on the remote SSH server back to the local client network. It facilitates inbound access rather than establishing a routed virtual network interface capable of handling raw Ethernet frames or performing internal subnet discovery.
- ✓
Setting up a TAP network interface tunnel
Why this is correct
A TAP interface operates at the Data Link Layer (Layer 2) of the OSI model, capturing and tunneling raw Ethernet frames. This enables protocols like ARP and allows attackers to perform comprehensive ping sweeps and layer 2 scanning through the pivot host.
- ✗
Dynamic port forwarding using an SSH SOCKS proxy (-D flag)
Why it's wrong here
Dynamic port forwarding creates a SOCKS proxy that routes TCP and UDP traffic application-by-application. It does not create a virtual network interface or handle raw layer 2 frames, meaning tools requiring raw sockets or ARP will fail completely.
Visual reference
Quick reference
VPN Protocol Comparison
| Protocol | Port | Encryption | Authentication | Use Case |
|---|---|---|---|---|
| IKEv2 / IPsec | UDP 500 / 4500 | AES-256 | Certificates / PSK | Site-to-site & remote access |
| SSL / TLS VPN | TCP 443 | TLS 1.3 | Certificates / MFA | Clientless remote access |
| L2TP / IPsec | UDP 1701 | AES (IPsec) | PSK / Certificates | Legacy remote access |
| WireGuard | UDP 51820 | ChaCha20 | Public keys | Modern high-performance VPN |
| PPTP | TCP 1723 | MPPE (weak) | MS-CHAPv2 | Legacy — avoid in production |
PPTP is considered insecure. IKEv2/IPsec and SSL VPN are the current recommended options.
About these practice questions
This PEN-200 question is part of Courseiva's 285-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 OffSec exam blueprint
This PEN-200 practice question is part of Courseiva's free OffSec 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 PEN-200 exam.