---
last_verified: 2026-03-14
service: OCI Networking
category: networking
oci_color: "#4F7B6E"
---

what: Software-defined networking layer in OCI. Includes VCN, subnets, gateways,
  load balancers, DNS, and connectivity options.

components:
  vcn:
    what: "Virtual Cloud Network — isolated network in OCI"
    cidr: "Supports multiple CIDR blocks, /16 to /30"
    max_per_region: 50
  subnet:
    what: "Subdivision of VCN, can be regional (spans all ADs)"
    types: ["public", "private"]
    recommendation: "Always use private subnets for databases and app servers"
  security_list:
    what: "Stateful firewall rules at subnet level"
    recommendation: "Prefer NSGs (Network Security Groups) for granular control"
  nsg:
    what: "Network Security Group — firewall rules at VNIC level"
    max_rules: "120 (ingress + egress combined per NSG)"
    recommendation: "Preferred over security lists for micro-segmentation"
  internet_gateway:
    what: "Enables internet access for public subnets"
  nat_gateway:
    what: "Enables outbound internet for private subnets"
  service_gateway:
    what: "Private access to OCI services (Object Storage, ADB, etc.)"
    recommendation: "Always use for database and storage access — no internet traversal"
  drg:
    what: "Dynamic Routing Gateway — hub for VCN peering and on-prem connectivity"
    supports: ["VCN peering", "FastConnect", "IPSec VPN", "Remote peering"]
  load_balancer:
    types:
      - name: "Flexible Load Balancer"
        what: "Layer 7 (HTTP/HTTPS) load balancer"
        bandwidth: "10 Mbps to 8 Gbps (flexible)"
      - name: "Network Load Balancer"
        what: "Layer 4 (TCP/UDP) load balancer"
        bandwidth: "Up to line rate"

connectivity:
  fastconnect:
    what: "Dedicated private connection to OCI (like AWS Direct Connect)"
    speeds: ["1 Gbps", "2 Gbps", "5 Gbps", "10 Gbps", "100 Gbps", "400 Gbps"]
    redundancy: "Always deploy 2 circuits for HA"
    notes: "Partner or co-location model, typical setup takes 2-4 weeks"
  ipsec_vpn:
    what: "Encrypted tunnel over internet"
    bandwidth: "Up to 250 Mbps per tunnel, aggregate with multiple tunnels"
    notes: "Good for dev/test or backup connectivity, not production data transfer"
  vcn_peering:
    local: "Within same region, no bandwidth limits"
    remote: "Cross-region via DRG, standard inter-region latency"

pricing:
  vcn: "Free"
  subnet: "Free"
  nat_gateway_per_hour: 0.0084
  service_gateway: "Free"
  drg_per_hour: 0.016
  fastconnect:
    port_per_month:
      1gbps: 180
      10gbps: 680
    data_ingress: "Free"
    data_egress: "Free over FastConnect"
  load_balancer:
    flexible_base: 0.014  # per hour
    per_mbps: 0.0013
  notes:
    - "Inter-region data transfer: $0.0085/GB"
    - "Internet egress: first 10 TB/month free, then $0.0085/GB"
    - "OCI egress pricing is significantly cheaper than AWS/Azure/GCP"

gotchas:
  - id: NET-001
    issue: "VCN CIDR blocks cannot overlap for peering"
    impact: "Plan CIDR ranges carefully for multi-VCN architectures"
    recommendation: "Use a documented IP addressing scheme before deployment"
  - id: NET-002
    issue: "FastConnect provisioning takes 2-4 weeks with partners"
    impact: "Can delay migration timelines"
    recommendation: "Start FastConnect procurement early, use VPN as interim"
  - id: NET-003
    issue: "Security lists apply to entire subnet, NSGs to specific VNICs"
    impact: "Security lists can be too broad for micro-segmentation"
    recommendation: "Use NSGs as primary, security lists as fallback"
