Cloud Networking Pre-requisites

• All the networks created by us in any cloud are private by default.
• Enabling public ip to the virtual machine
  • CSP will have pool of public ip addresses out of which one ip is selected randomly and assigned to your network interface.
  • When the vm is shutdown, the public ip will be released and it will go back to the pool.
  • If we want the public ip to be same even after stopping and starting the vm, we need to make static public ip reservations.

Auto Scaling (Elasticity)

• When the number of servers hosting the customer facing applications over internet are scaled, each server gets its own private ip. Public ip also can be allocated
• Questions:
  • Do we really need a public ip for each vm
  • What is that public which customers are going to use to access the application.
    
• OSI Model of Networking
  
  
• In the above case, the same application is scaled so we can use a Load Balancer which is Layer 4 aware
• Load Balancer performs
  • Health checks/probes to ensure whether the service is up or not.
  • For Healthy servers, the traffic will be forwarded in Round Robin Fashion
• Now, The vm’s can be private and its enough if the load balancer has public ip.
• Layer 7:
  

Hybrid Networking

• Site-to-Site VPN
  
• Next Steps:
  • Multiples sites to a network vpn connection.

Disaster Recovery and Multi Region Setups

• Active-Passive:
  
• Active-Active: