1Z0-1085-26 Core Oci Services Practice Question
You are troubleshooting a connectivity issue where an on-premises server cannot reach an OCI compute instance over an IPsec VPN tunnel. The security list and NSG rules are verified as correct. What is another common OCI networking configuration that must be checked?
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
✓
Ensure the VCN route table has a rule pointing on-premises CIDR to the DRG
The VCN route table must have a rule pointing traffic destined for the on-premises subnet to the Dynamic Routing Gateway (DRG).
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Confirm that the subnet has a Service Gateway attached
Why it's wrong here
Service Gateways are for regional Oracle services, not on-premises VPN.
- ✗
Check that the compute instance has a public IP address assigned
Why it's wrong here
Private compute instances communicate over VPN using private IP addresses.
- ✗
Verify that an Internet Gateway is attached to the VCN
Why it's wrong here
IPsec VPN traffic does not use Internet Gateways.
- ✓
Ensure the VCN route table has a rule pointing on-premises CIDR to the DRG
Why this is correct
Without a route table entry pointing to the DRG, return or outbound packets cannot traverse the VPN.
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.