[...] ServerInstance: Type: "AWS::EC2::Instance" Properties: ImageId: "ami-0e1ab783dc9489f34" # Centos7 for paris InstanceType: t3.2xlarge AvailabilityZone: !GetAtt FortiVPCFrontNet.AvailabilityZone KeyName: Ref: KeyName SubnetId: Ref: FortiVPCBackNet SecurityGroupIds: - !Ref ServerSecGroup Server2Instance: Type: "AWS::EC2::Instance" Properties: ImageId: "ami-0e1ab783dc9489f34" # Centos7 for paris [...]