Instance A (MongoDB):

• Subnet ID: subnet-1abcdef2
  • CIDR 10.0.5.0/24
• VPC ID: vpc-3a456b7c
• Private IP: 10.0.5.158
• Security Group: TCP Port (27017)
  • 34.102.207.234/32
  • sg-1dde247a (default)

Instance B:

• Subnet ID: subnet-1abcdef2
  • CIDR 10.0.5.0/24
• VPC ID: vpc-3a456b7c
• Private IP: 10.0.5.98
• Security Group:
  • sg-1dde247a (default)

You want to access the MongoDB instance from your application running on Instance B.