156-315.81.20 Advanced VPN Design Practice Question
Which THREE of the following are prerequisites for successful IKEv2 VPN establishment between a Check Point gateway and a third-party peer?
⚠ Common exam trap
Candidates often overlook ID types and authentication mismatches, assuming that matching encryption proposals alone guarantees a successful IKEv2 tunnel.
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
✓
Matching IKEv2 Proposal encryption and integrity suites.
Successful IKEv2 negotiation requires precise alignment on cryptographic standards, authentication methods, and identity validation. These prerequisites prevent unauthorized access and ensure that both endpoints can securely negotiate the SA keys. Understanding these requirements is essential for troubleshooting interoperability issues, as even minor misalignments in proposal selection or ID formats will prevent the tunnel from successfully transitioning to the 'Up' state.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
Matching IKEv2 Proposal encryption and integrity suites.
Why this is correct
IKEv2 requires both sides to agree on a specific cryptographic proposal. If the algorithms for encryption and integrity do not match, the negotiation will fail immediately during the IKE_SA_INIT stage. Ensuring these suites align is the most fundamental requirement for any successful VPN tunnel initialization between disparate hardware vendors.
- ✗
Both gateways must use the same vendor OS version.
Why it's wrong here
VPN protocols like IKEv2 are standards-based, and interoperability is designed to work regardless of the vendor or OS version. While specific software versions might have bugs, there is no architectural requirement for both peers to run the same vendor or OS, provided they adhere to the RFC standards.
- ✓
Matching authentication method (e.g., Pre-shared secret or Certificate).
Why this is correct
The authentication method used in the IKE_AUTH phase must be identical on both peers. If one side expects a certificate-based handshake while the other uses a pre-shared key, the authentication process will fail. Both sides must agree on the methodology to ensure the exchange of identity information is valid.
- ✓
Matching IKEv2 Local and Remote ID types.
Why this is correct
IKEv2 uses identities (IDi and IDr) to identify the peers. If the ID type (e.g., FQDN, IP, or Email) is not configured correctly on both sides, the peer will reject the identity provided, causing the tunnel setup to fail even if the pre-shared key or certificate is technically correct.
- ✗
Both gateways must have the same management server IP.
Why it's wrong here
The management server IP is used for administration and policy deployment within the Check Point ecosystem. It has no bearing on the VPN tunnel negotiation process between two independent security gateways. Peers communicate directly over the VPN gateway interfaces, independent of the central management server's network location.
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 156-315.81.20 question is part of Courseiva's 210-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 Check Point exam blueprint
This 156-315.81.20 practice question is part of Courseiva's free Check Point 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 156-315.81.20 exam.