PCNSE Secure Access and VPN Practice Question
A network engineer configures an IPSec tunnel with multiple proxy IDs for different subnets. After committing, only one proxy ID establishes IPsec SAs. What should the engineer check?
⚠ Common exam trap
Many exam-takers assume the issue is with crypto profile mismatches or IKE gateway settings, but Palo Alto specifically tests the knowledge that each proxy ID consumes a separate tunnel slot, and the tunnel count limit is a common misconfiguration that causes only one proxy ID to work.
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
✓
The number of concurrent tunnels allowed.
Palo Alto Networks firewalls have a default limit on the number of concurrent IPsec tunnels. When multiple proxy IDs are configured, each proxy ID requires its own IPsec security association (SA). If the tunnel limit is reached, only the first proxy ID establishes SAs, and subsequent ones fail. Checking and increasing the 'Number of Tunnels' setting under the tunnel interface or global IPSec configuration resolves this.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
The number of concurrent tunnels allowed.
Why this is correct
Correct. The firewall may limit concurrent SAs per gateway.
- ✗
The IPSec crypto profile.
Why it's wrong here
Incorrect. Crypto profile defines algorithms, not capacity.
- ✗
The IKE gateway mode.
Why it's wrong here
Incorrect. Mode affects IKE version, not number of SAs.
- ✗
The tunnel monitor settings.
Why it's wrong here
Incorrect. Monitor settings affect passive monitoring, not SA establishment.
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.
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JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This PCNSE practice question is part of Courseiva's free Palo Alto Networks 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 PCNSE exam.