Extended Network Capabilities
The resources in this category extend the core functionality of networking in OCI. They are all optional services that allow for additional connectivity options.
NAT Gateway
NAT is a networking technique to give private network access to the internet without assigning each host a public IP address. The hosts can make connections to the internet and receive responses but cannot accept inbound connections.
When a host in the private network initiates an Internet-bound connection, the NAT device’s public IP address becomes the source IP address for the outbound traffic. The response traffic from the internet uses that public IP address as the destination IP address. The NAT device then routes the response to the host in the private network that initiated the connection.
Load Balancer
A load balancer improves resource utilization, facilitates scaling, and helps ensure high availability. This service provides automatic traffic distribution from one entry point to multiple servers reachable within a VCN. The load balancer can have either a public or private IP address and dedicated bandwidth.
Service Gateway
Oracle Cloud offers a range of platform services such as Object Storage, Autonomous Database, Analytics Cloud, Identity Cloud Service and many more. These services have public IP addresses that you usually access over the internet.
A Service Gateway lets your VCN privately access these services without exposing the data to the public internet. The resources in the VCN can be in a private subnet and use only private IP addresses. The traffic from the VCN to the Oracle service travels over the Oracle network fabric and never goes across the internet.
Local Peering Gateway
Resources in different VCN’s can only communicate if local peering is explicitly granted. Local peering between two VCN’s can either be achieved through each VCN being attached to the same DRG (and routing tables being configured appropriately) or by using a Local Peering Gateway (LPG). An LPG is a component in a VCN for routing traffic to a locally peered VCN. As part of configuring the VCNs, each administrator must create an LPG for their VCN. Although there can be some performance advantages to using LPG’s, Oracle recommends that local peering be achieved through a common DRG as this offers a greater degree of flexibility.