Download Oracle Cloud Infrastructure 2025 Networking Professional.1Z0-1124-25.Pass4Success.2026-01-27.16q.vcex

Zero Trust Context: Assumes no inherent trust, requiring explicit controls at all network stages.Evaluate Principles:Implicit Trust: Assumes trust, opposite of Zero Trust; incorrect.Least Privilege: Grants minimal access, explicitly enforced; aligns with Zero Trust.Perimeter Security: Relies on boundary protection, not Zero Trust; incorrect.Network Segmentation: Isolates networks, a tactic not a principle; incomplete.Conclusion: Least Privilege is the core principle for explicit access control.Zero Trust Packet Routing in OCI emphasizes Least Privilege. The Oracle Networking Professional study guide states, 'The Least Privilege principle in Zero Trust requires that access controls be explicitly defined and enforced at every network communication stage, ensuring no implicit trust' (OCI Networking Documentation, Section: Zero Trust Networking). This drives granular security policies.

Goal: Apply least privilege for Cloud Shell to run diagnostics (ping, traceroute, nc) within a VCN.Option A: Read permission on all virtual-network-family resources is too broad, granting unnecessary access beyond diagnostics---violates least privilege.Option B: Instance Principals use temporary credentials tied to the Cloud Shell instance, enhancing security. A dynamic group with ''read'' and ''use'' permissions on NSGs and VNICs allows inspecting configurations and running diagnostics (e.g., via VNICs), meeting the exact need---correct.Option C: Inspect permission only provides metadata access, insufficient for running diagnostics (e.g., no ''use'' for traffic)---incorrect.Option D: Use permission on virtual-network-family at tenancy level is overly permissive, granting access to all network resources---violates least privilege.Conclusion: Option B is the most restrictive and secure, aligning with least privilege.Oracle states:'Instance Principals allow services like Cloud Shell to authenticate without static credentials. Policies with 'read' and 'use' on specific resources (e.g., network-security-groups, vnics) enable diagnostics while adhering to least privilege.'This supports Option B. Reference: Instance Principals - Oracle Help Center (docs.oracle.com/en-us/iaas/Content/Identity/Tasks/instanceprincipals.htm).

Symptoms: VPN tunnel drops intermittently despite stable internet and IKE settings.VPN Components: Requires IKE (UDP 500/4500) and ESP (IP 50) traffic.Evaluate Options:A: Incorrect CPE IP would prevent tunnel establishment, not intermittent drops; incorrect.B: DRG outage would cause full downtime, not intermittent; unlikely.C: Security rules blocking IKE/ESP intermittently (e.g., rate limiting) is common; most likely.D: NAT-Traversal issues typically prevent initial setup, not intermittent drops; less likely.Conclusion: Security rule misconfiguration is the most probable cause.VPN stability depends on unblocked IKE and ESP traffic. The Oracle Networking Professional study guide notes, 'Intermittent VPN tunnel drops are often caused by security rules or firewalls blocking IKE (UDP 500/4500) or ESP (IP Protocol 50) traffic' (OCI Networking Documentation, Section: Site-to-Site VPN Troubleshooting). This aligns with the scenario's symptoms.

Problem: OKE web tier pods cannot reach the application tier.Traffic Flow: Web tier (OKE) initiates outbound (egress) traffic to application tier (port 8080).NSG Role: Controls traffic at VNIC level; must allow egress from OKE and ingress to app tier.Evaluate Options:A: Missing egress rule on OKE NSG blocks traffic; plausible but incomplete context.B: Ingress on OKE NSG affects incoming traffic, not outbound to app tier; incorrect.C: No ingress on OKE NSG doesn't block egress to app tier; incorrect.D: Egress limited to internet blocks app tier access (port 8080); most likely.Conclusion: Missing egress rule to app tier NSG is the primary issue.NSGs require explicit egress rules for outbound traffic. The Oracle Networking Professional study guide notes, 'For OKE pods to communicate with other tiers, the node pool's NSG must include egress rules to the destination NSG or CIDR on the required ports' (OCI Networking Documentation, Section: Network Security Groups with OKE). Option D reflects a common misconfiguration in IaC setups.

Concern: IPSec overhead reduces effective MTU.MTU Impact: Must avoid fragmentation, which degrades performance.Evaluate Factors:A: Bandwidth doesn't dictate MTU; incorrect.B: Smallest MTU in path (path MTU) prevents fragmentation; most critical.C: Ethernet MTU is a factor but not the limiting one; incomplete.D: DRG fragmentation settings are secondary to path MTU; incorrect.Conclusion: Path MTU is the key determinant to avoid fragmentation.IPSec reduces MTU due to headers. The Oracle Networking Professional study guide explains, 'When configuring IPSec over FastConnect, the most important factor is the smallest MTU supported along the entire path to prevent fragmentation and ensure efficient traffic flow' (OCI Networking Documentation, Section: IPSec over FastConnect). Path MTU discovery is critical.

Identify the Goal: Troubleshoot efficiently to determine if stateful inspection is causing intermittent connectivity issues.Option A Evaluation: Disabling stateful inspection globally removes all security checks, potentially restoring connectivity but disrupting the entire VCN's security. This is inefficient and risky.Option B Evaluation: Creating a bypass rule for the application server avoids inspection, which could confirm the issue but weakens security for that server. It's a workaround, not a diagnostic step, and requires policy changes during troubleshooting.Option C Evaluation: Reviewing firewall logs for denied traffic is targeted and non-disruptive. Logs show if stateful inspection is dropping packets (e.g., due to session timeouts or rule mismatches), directly identifying the cause without altering configurations.Option D Evaluation: Recreating the firewall is highly disruptive, time-consuming, and doesn't guarantee insight into the current issue. It's not a troubleshooting step.Conclusion: Option C is the most efficient, as it leverages logs for precise diagnosis without impacting operations.Per Oracle's Network Firewall documentation:'Network Firewall logs provide detailed information about allowed and denied traffic, including source/destination IPs, ports, and protocols. Use logs to troubleshoot connectivity issues by identifying dropped packets due to stateful inspection or rule mismatches.''Stateful inspection tracks connection states; misconfigurations can lead to dropped sessions.'This confirms logs are the best tool for diagnosing stateful inspection issues. Reference: Network Firewall Overview - Oracle Help Center (docs.oracle.com/en-us/iaas/Content/NetworkFirewall/overview.htm).

Goal: Minimize downtime in blue/green deployment with ALB.ALB Capabilities: Supports weighted routing for gradual traffic shifts.Evaluate Options:A: Immediate switch risks downtime if 'green' fails; less efficient.B: Listener swap causes abrupt change; not optimal.C: Gradual shift with weights ensures smooth transition; most efficient.D: Forcing 'blue' unhealthy is disruptive and hacky; inefficient.Conclusion: Weighted routing provides the smoothest transition.ALB supports blue/green via routing rules. The Oracle Networking Professional study guide states, 'Application Load Balancer's routing rules allow weighted traffic distribution between backend sets, enabling blue/green deployments with minimal downtime' (OCI Networking Documentation, Section: Load Balancer Routing). This method ensures stability during updates.

Requirements: High throughput, low latency, TCP, persistence, private endpoints.Load Balancer Options:ALB: Layer 7, higher overhead, HTTP-focused.NLB: Layer 4, low overhead, TCP/UDP optimized.Global LB: Global routing, not regional focus.Evaluate Options:A: ALB with IP Hash has overhead; less optimal.B: NLB with 5-Tuple Hash offers low latency, persistence, private support; best fit.C: Global LB with cookies is HTTP-based; incorrect.D: HTTP focus is irrelevant for raw TCP; incorrect.Conclusion: NLB with 5-Tuple Hash meets all criteria.NLB is ideal for high-performance TCP. The Oracle Networking Professional study guide states, 'Network Load Balancer provides low-latency, high-throughput TCP load balancing with 5-Tuple Hash persistence, supporting private endpoints for secure, high-volume applications' (OCI Networking Documentation, Section: Network Load Balancer). This aligns with financial app needs.

Requirement: Private communication between VCNs in different OCI regions via DRG.Option A: LPGs are for same-region VCN peering, not cross-region---incorrect.Option B: Service Gateways are for OCI service access, not VCN-to-VCN routing---incorrect.Option C: Attaching both VCNs to a single DRG (via Remote Peering Connections implicitly) and configuring route tables enables cross-region communication over OCI's backbone. This is the standard approach.Option D: Internet Gateways use public IPs, which is insecure and not private---incorrect.Conclusion: Option C is the necessary configuration for DRG-based cross-region connectivity.Oracle documentation confirms:'To connect VCNs in different regions, attach each to a DRG using Remote Peering Connections (RPCs). Configure DRG route tables to route traffic between VCN CIDRs.'Option C reflects this setup (RPCs are implied). Reference: VCN Peering Overview - Oracle Help Center (docs.oracle.com/en-us/iaas/Content/Network/Tasks/remoteVCNpeering.htm).

Requirement: Private VCN connection across tenancies.Services:Internet Gateway: Public access; incorrect.Service Gateway: OCI services, not VCNs; incorrect.RPC: Cross-tenancy private peering; correct.DRG with LPG: LPG is intra-region, not cross-tenancy; incorrect.Evaluate Options:A: Public; incorrect.B: Service-focused; incorrect.C: Designed for this scenario; correct.D: Misaligned components; incorrect.Conclusion: RPC is the right service.RPC enables cross-tenancy peering. The Oracle Networking Professional study guide notes, 'Remote Peering Connections (RPCs) establish private connectivity between VCNs in different tenancies over OCI's private backbone' (OCI Networking Documentation, Section: Remote Peering Connections). This ensures no public internet traversal.

Goal: Filter Flow Logs for traffic rejected by a specific security list rule.Option A: ''action'' = ''REJECT'' identifies rejected traffic; ''securityListRule'' with rule ID pinpoints the exact rule---correct.Option B: ''status'' and ''securityRule'' aren't standard Flow Log fields (''action'' and ''securityListRule'' are)---incorrect.Option C: ''direction'' and ''port'' filter traffic but don't specify rejection or rule---incorrect.Option D: ''type'' and ''rule'' aren't valid Flow Log fields---incorrect.Conclusion: Option A is the precise filtering method.Oracle states:'In Flow Logs, use the 'action' field ('REJECT') and 'securityListRule' field (rule ID) to filter traffic rejected by a specific security list rule.''This validates Option A. Reference: Flow Logs Fields - Oracle Help Center (docs.oracle.com/en-us/iaas/Content/Network/Concepts/flowlogs.htm#fields).