Lesson 5: OCI Networking Services

Virtual Cloud Network, Gateways, Peering, VCN Security, Load Balancer

Virtual Cloud Network (VCN)

• A private network in Software layer which lives in an OCI Region.

• Enables OCI resources to securely communicate with Internet, other instances or on-premises(内部, 本地) data center.

• Highly Available, Scalable and Secure.

How to establish a VCN

• Private address pool assigned to a VCN

• Subnets in private address pool

Gateways

Internet Gateway

It provides a path for network traffic between your VCN and the internet.

Nat Gateway

It gives cloud resources without public IP addresses access to the internet without exposing those resources to incoming internet connections. 它提供的云资源无需公共IP地址即可访问Internet，而不会将这些资源暴露于传入的Internet连接中。

Dynamic Routing Gateway (DRG)

when connecting your existing on-premises network to your virtual cloud network (VCN).

There are 2 mechanisms of DRG:

• VPN Connect (IPSec VPN)

  An encrypted connection over the internet between between your on-premises network (a data center or corporate LAN) and your Oracle virtual cloud network (VCN)

• FastConnect

  An dedicated, private connection between your data center and Oracle Cloud Infrastructure, bypasses the internet (绕过internet)

Service Gateway

which lets resources in VCN access public services such as Object Storage, but without using an internet or NAT gateway. So your traffic is not going over the internet

VCN Security

• Firewall rules to protect subnets

• Network Security Group consists of set of rules applied only for VNICs

Peering

communicate to other VCNs, it has 2 types of peering:

• Local VCN peering

  Connect 2 VCNs in the same region so that their resources can communicate using private IP addresses.

  

• Remote VCN peering

  Connect 2 VCNS in different regions so that their resources can communicate using private IP addresses.

  

Load Balancer

It provides automated traffic distribution from one entry point to multiple servers reachable from your virtual cloud network (VCN) A load balancer improves resource utilization, facilitates scaling, fault tolerance and helps ensure high availability. You can configure multiple load balancing policies and application-specific health checks to ensure that the load balancer directs traffic only to healthy instances.

It has 2 types of LB:

• Public Load Balancer

  To accept traffic from the internet, you create a public load balancer.

• Private Load Balancer

  To isolate your load balancer from the internet and simplify your security posture 处境