1Z0-1085-26 Core Oci Services Practice Question
An administrator is configuring a site-to-site VPN connection between an on-premises data center and an OCI VCN. During testing, packets are being dropped because the on-premises firewall expects a specific encryption algorithm and IPsec tunnel parameters that do not match OCI defaults. How can this be resolved?
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
✓
Create a custom IPsec connection specifying the exact Phase 1 and Phase 2 parameters required by the on-premises firewall.
Custom IPsec connection configurations allow administrators to specify exact Phase 1 and Phase 2 tunnel parameters (such as encryption and authentication algorithms) to match on-premises VPN device requirements.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Modify the default VCN Security List to allow IPsec encapsulation protocols.
Why it's wrong here
Security lists do not manage IPsec tunnel encryption parameters or cryptographic phase settings.
- ✗
Replace the Dynamic Routing Gateway with a NAT Gateway to bypass IPsec encryption.
Why it's wrong here
NAT Gateways do not support VPN tunneling or IPsec encapsulation.
- ✗
Install an OCI Compute instance running a software VPN appliance to override OCI IPSec defaults.
Why it's wrong here
While software appliances are an option, OCI natively supports custom IPsec parameters without extra compute overhead.
- ✓
Create a custom IPsec connection specifying the exact Phase 1 and Phase 2 parameters required by the on-premises firewall.
Why this is correct
Custom IPsec configuration allows matching specific cryptographic requirements of third-party firewalls.
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 and reviewed by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
Last reviewed August 2026 · checked against the official Oracle exam blueprint
This 1Z0-1085-26 practice question is part of Courseiva's free Oracle 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 1Z0-1085-26 exam.