Oracle cloud

Oracle OCI Networking: A Blueprint for Cloud Connectivity

Networking in Oracle OCI involves:

  • Setting up virtual versions of traditional network components in Oracle Cloud Infrastructure (OCI).
  • Utilizing virtual cloud networks (VCNs) and subnets for organizing cloud resources.
  • Managing network security and traffic control through features like security lists, network security groups, and dynamic routing gateways.
  • Enabling connectivity options like FastConnect, VPN, and Internet Gateways for varied access needs​

Introduction to Networking in Oracle OCI

Networking in OCI

Oracle Cloud Infrastructure (OCI) offers a comprehensive, flexible networking architecture to support complex cloud environments.

The networking in OCI is foundational to deploying and managing cloud resources, ensuring secure and efficient connectivity.

  1. Overview of OCI Networking:
    • Oracle Cloud Infrastructure Networking allows for the creation of virtual versions of traditional network components, facilitating a highly customizable and secure cloud network environment.
    • It encompasses a range of services and features designed to support simple and highly complex network configurations, adapting to diverse business requirements​​​​​​.
  2. Role of Virtual Cloud Networks (VCNs) and Subnets:
    • VCNs in OCI are akin to traditional networks within the Oracle Cloud, offering complete control over the network environment. They serve as the backbone of cloud networking in OCI.
    • Subnets, a subdivision of VCNs, are crucial in organizing and securing cloud resources. They enable the segregation of resources within a VCN and can be tailored to specific availability domains or span across a region​​​​​​.

Core Networking Components in Oracle OCI

Oracle OCI’s networking is built upon various core components that provide the foundation for cloud networking.

  1. Default Components in a VCN:
    • Route Tables: These are used to direct network traffic within the VCN and to external destinations. A default route table has no predefined rules and can be customized according to networking needs.
    • Security Lists: Acting as a virtual firewall, the default security list includes basic security rules that govern traffic to and from VCN resources. Users can modify these rules or create custom security lists.
    • DHCP Options: The default set of DHCP options automatically manages IP address allocation within the VCN, with the ability to customize settings as required​​.
  2. Connectivity Choices in OCI:
    • Public vs. Private Subnets: Subnets in OCI can be designated as public or private. Public subnets allow resources like compute instances to have internet access and public IP addresses, whereas private subnets restrict direct internet access, enhancing security.
    • IP Address Assignment: OCI allows for flexible IP address assignment. Each instance within a subnet receives a private IP address, with the option to assign public IP addresses for resources in public subnets. The assignment can be automatic or user-defined​​​​.

Understanding these components and their interaction within Oracle Cloud Infrastructure is key to effectively designing and managing cloud networks.

Advanced Networking Features in Oracle OCI

Oracle OCI offers advanced networking features that cater to diverse operational needs, ensuring high availability, scalability, and performance.

  1. Flexible Load Balancer and Network Load Balancer:
    • Flexible Load Balancer: Provides Layer 4 (TCP) and Layer 7 (HTTP) proxy load balancing. It supports SSL offload/termination cookie-based session persistence and offers guaranteed and flexible bandwidth.
    • Network Load Balancer: Focuses on low latency and is optimized for long-lived connections. It operates at Layers 3 and 4 (TCP/UDP/ICMP), preserving source and destination IP, and is free of charge​​.
  2. FastConnect:
    • Offers high availability and global traffic shaping for applications. FastConnect provides predictable connectivity via deterministic paths and supports public and private peering. It is integral for enterprises requiring reliable, high-bandwidth connections between their data centers and Oracle Cloud Infrastructure​​.
  3. DNS Services:
    • Public DNS: Ensures high availability and global traffic shaping, featuring active failover, ratio load balancing, and geolocation steering.
    • Private DNS: Allows private DNS zones in VCNs, facilitating DNS resolution between VCNs and connectivity between cloud and on-premises networks​​.
  4. RDMA Cluster Networking and Global Connectivity:
    • RDMA (Remote Direct Memory Access) over converged Ethernet and a 100 Gbps network support high-performance computing clusters, essential for workloads requiring microsecond latencies.
    • Enhancements in global connectivity, like the dynamic routing gateway, further augment the networking capabilities of Oracle OCI, catering to complex, multi-region deployments​​​​.

Top 5 Best Practices for OCI Networking

Effective management of OCI networking involves adhering to best practices that ensure optimal performance and security.

  1. Implement Robust Security Measures:
    • Utilize security lists and network security groups to control traffic flow, ensuring only authorized access to resources.
    • Regularly update security rules in response to changing network needs and potential threats​​.
  2. Optimize Route Tables:
    • Carefully configure route tables to efficiently manage traffic within the VCN and external networks.
    • Ensure route rules are aligned with the network architecture and operational objectives​​.
  3. Leverage FastConnect for Reliable Connectivity:
    • Use FastConnect for high-bandwidth, low-latency connections, especially for hybrid cloud environments and critical workloads requiring dependable network performance​​.
  4. Effective Use of Load Balancers:
    • Deploy Flexible and Network Load Balancers strategically to ensure even traffic distribution and high availability.
    • Configure load balancers to meet specific application requirements, like session persistence and SSL termination​​.
  5. Regular Network Monitoring and Analysis:
    • Continuously monitor network performance and usage patterns.
    • Utilize tools like Network Path Analyzer and Network Visualizer for in-depth network analysis and troubleshooting​​​​​​.

By adhering to these best practices, businesses can build a resilient, secure, and efficient network infrastructure in Oracle Cloud Infrastructure, effectively supporting their cloud operations and strategic goals.

Frequently Asked Questions (FAQ)

  1. How does Oracle OCI ensure network security?
    • OCI employs multiple layers of security, including network security groups (NSGs), security lists, and dynamic routing gateways (DRGs) to control and monitor traffic. Advanced features like private DNS and virtual firewalls further enhance security​​​​.
  2. What connectivity options are available in Oracle OCI?
    • OCI offers various connectivity options like FastConnect for dedicated high-bandwidth connections, VPN for secure remote access, and Internet Gateways for public internet connectivity. There are also options for private peering and public DNS services​​​​.
  3. Can OCI’s network support high-performance computing (HPC) workloads?
    • Yes, OCI’s network supports HPC workloads with features like RDMA cluster networking, providing low-latency and high-throughput network capabilities essential for HPC applications​​​​.
  4. How are IP addresses managed in Oracle OCI?
    • OCI provides flexible IP address management within VCNs, allowing for both automatic and manual IP address assignment to instances. This includes private and public IP address options based on the subnet type​​.
  5. What are the best practices for load balancing in OCI?
    • Utilize OCI’s Flexible Load Balancer and Network Load Balancer based on your specific requirements, such as traffic type, required latency, and connection persistence. Proper configuration and regular monitoring are key for optimal load-balancing performance​​.


The strategic importance of robust networking in Oracle Cloud Infrastructure cannot be overstated. It is the backbone that supports the performance, security, and seamless operations of cloud-based applications and services.

With its comprehensive suite of networking features, from advanced load balancing to intricate security measures, OCI provides the tools and capabilities necessary for businesses to thrive in a cloud environment.


  • Fredrik Filipsson

    Fredrik Filipsson brings two decades of Oracle license management experience, including a nine-year tenure at Oracle and 11 years in Oracle license consulting. His expertise extends across leading IT corporations like IBM, enriching his profile with a broad spectrum of software and cloud projects. Filipsson's proficiency encompasses IBM, SAP, Microsoft, and Salesforce platforms, alongside significant involvement in Microsoft Copilot and AI initiatives, enhancing organizational efficiency.