Install OpenShift v4 on VMWare:

OpenShift v4 supports only L4 Load balancer:

L4 (Layer 4) and L7 (Layer 7) load balancers operate at different layers of the OSI (Open Systems Interconnection) model, affecting how they manage traffic and the types of decisions they can make.

1. Layer 4 (L4) Load Balancer:
2. • Layer: Works at the Transport Layer (Layer 4) of the OSI model.
   • Functionality: L4 load balancers route traffic based on data from network and transport layer protocols, such as IP, TCP, and UDP.
   • Decisions Based On: IP addresses and TCP/UDP ports.
   • Performance: Typically faster and more efficient in terms of raw throughput, as they make routing decisions based on simpler and lower-level criteria.
   • Use Case: Ideal for routing traffic for simple, less sophisticated load balancing needs, where application-level decisions (like HTTP headers, cookies, etc.) are not required.
3. Layer 7 (L7) Load Balancer:
4. • Layer: Operates at the Application Layer (Layer 7) of the OSI model.
   • Functionality: L7 load balancers route traffic based on data from application layer protocols, such as HTTP/HTTPS.
   • Decisions Based On: Content of the message, including headers, message body, URLs, and other HTTP-specific characteristics.
   • Performance: Generally slower than L4 load balancers due to the more complex decision-making process, but more flexible and intelligent in traffic distribution.
   • Use Case: Suitable for complex load balancing needs, such as routing based on cookies, session IDs, HTTP headers, and other application-specific data.

Ports Requirements:

When installing OpenShift v4 on VMware, several network ports need to be open for proper communication and functionality. Here’s a list of the required ports:

1. Master Nodes:
   • TCP 6443: Kubernetes API server.
   • TCP 22623: Machine Config server.
2. Worker Nodes:
   • TCP 80: HTTP for ingress traffic.
   • TCP 443: HTTPS for ingress traffic.
   • TCP 30000-32767: NodePort Services, by default.
3. etcd Nodes (usually co-located with master nodes):
   • TCP 2379-2380: etcd server client API.
4. Other Ports:
   • UDP 4789: VXLAN (for the SDN).
   • UDP 9000-9999: Host network (used for NodePort services).
5. Internet Access:
   • Outbound internet access is also required for nodes to access container registries for image pulls and updates.

Please note: There are several other port numbers required between Master to Master, Worker to Worker, Worker to Master, and Master to workers. Kindly refer the Red Hat manual with the updates.