Understanding Network Interface in AWS , usage and Advantages

Just like your normal virtual machines you need to attach an network interface card to your ec2 instances in AWS for making them available on internet. It also gives you flexibility to attach more than one NIC card to your instance. Depending on the kind of instance you running you can add network interface card to them.  Like you can attach upto 3 network interface card as of now to your micro instance in AWS.



Another advantage of using the network interface card and assigning a elastic ip to it is even if you terminate the instance than also you won’t lose your ip address unlike the classic version of amazon in which if you terminate your instance your elastic ip address would be lost. Also depending on the architecture of your environment in the AWS you would need to assign the NIC cards to your instances. For e.g if you are hosting multiple web applications and need to assign SSL to multiple applications than you would need to create and assign multiple NIC card to your instances in order to associate multiple Elastic ips as only a single SSL certificate can is supported on an ip. So if you running multiple web application and need to assign SSL certificates on them than you need to assign multiple NIC Cards and ip address to those instances.