# AWS.Networking.ENI
<a name="node-eni"></a>

A network interface is a logical networking component in a VPC that represents a virtual network card. A network interface is assigned an IP address either automatically or manually based on its subnet. After you deploy an Amazon EC2 instance in a subnet, you can attach a network interface to it, or detach a network interface from that Amazon EC2 instance and reattach to another Amazon EC2 instance in that subnet. The device index identifies the position in the attachment order.

## Syntax
<a name="node-eni-syntax"></a>

```
tosca.nodes.AWS.Networking.ENI:
  properties:
    device\$1index: Integer
    source\$1dest\$1check: Boolean
    tags: List
  requirements:
    subnet: String
    security\$1groups: List
```

## Properties
<a name="node-eni-properties"></a>

 `device_index`    
The device index must be greater than zero.  
Required: Yes  
Type: Integer

 `source_dest_check`    
Indicates whether the network interface performs source/destination checking. A value of `true` means that checking is enabled, and `false` means that checking is disabled.  
Allowed value: true, false  
Default: true  
Required: No  
Type: Boolean

 `tags`    
The tags to be attached to the resource.  
Required: No  
Type: List

## Requirements
<a name="node-eni-requirements"></a>

 `subnet`    
An [AWS.Networking.Subnet](node-subnet.md) node.  
Required: Yes  
Type: String

 `security_groups`    
An [AWS.Networking.SecurityGroup](node-networking-security-group.md) node.  
Required: No  
Type: String

## Example
<a name="node-eni-example"></a>

```
SampleENI:
  type: tosca.nodes.AWS.Networking.ENI
  properties:
    device_index: 5
    source_dest_check: true
    tags:
      - "Name=SampleVPC"
      - "Environment=Testing" 
  requirements:
    subnet: SampleSubnet
    security_groups:
      - SampleSecurityGroup01
      - SampleSecurityGroup02
```