security list is a set of firewall rules to allow/block traffic to and from the Instance.
subnets can have upto 5 security lists
OCI Follows a white list model that means we need to allow traffic even for the vms with in same subnets
31 secondary private IPs can have to a NIC in a VM
OCI Public Load Balancer has a Oracle provided public IP and we cannot chose it and same for NAT Gateway, DRG, AWH, Internet gatewy etc.
ephermal are public ips only exist till vm is running and changes on reboot
Load BAlancer, we need to check where the LBs and backend servers are, like if both are in same subnet, we need to add an ingress rule into the security list for port 80 or the port you want to expose to both the LB and the backend server.