NSE7_SDW Security Profiles Routing And IPsec Practice Question
An IPsec VPN tunnel used as an SD-WAN member is experiencing intermittent flapping due to DPD (Dead Peer Detection) timeout issues over a high-latency satellite link. How should the administrator adjust the Phase 1 IPsec settings on FortiOS to stabilize the tunnel without completely disabling failure detection?
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
✓
Increase the DPD retry count and interval settings under the IPsec Phase 1 configuration
On high-latency or high-jitter links like satellite connections, the default DPD retry count and interval may be too aggressive. Increasing the DPD retry count and/or interval or switching the DPD mode to 'on-idle' or 'on-demand' helps prevent false drops.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Disable DPD entirely so the FortiGate never tears down the tunnel
Why it's wrong here
Disabling DPD leaves dead tunnels active, preventing SD-WAN from failing over to healthy links.
- ✗
Enable NP6/NP7 hardware offloading for Phase 1 SA renegotiation
Why it's wrong here
Hardware offload settings do not alter DPD timer thresholds.
- ✗
Change the IPsec phase 1 mode from Main mode to Aggressive mode
Why it's wrong here
Aggressive mode is less secure and does not impact DPD timeout behavior.
- ✓
Increase the DPD retry count and interval settings under the IPsec Phase 1 configuration
Why this is correct
Correct. Increasing the DPD interval and retry count gives the satellite link more time to respond to liveness probes, preventing unnecessary flapping.
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 NSE7_SDW question is part of Courseiva's 92-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 August 2026 · checked against the official Fortinet exam blueprint
This NSE7_SDW practice question is part of Courseiva's free Fortinet 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 NSE7_SDW exam.