**Example 1: To attach a network interface to an instance** The following ``attach-network-interface`` example attaches the specified network interface to the specified instance. :: aws ec2 attach-network-interface \ --network-interface-id eni-0dc56a8d4640ad10a \ --instance-id i-1234567890abcdef0 \ --device-index 1 Output:: { "AttachmentId": "eni-attach-01a8fc87363f07cf9" } For more information, see `Elastic network interfaces <https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/using-eni.html>`__ in the *Amazon EC2 User Guide*. **Example 2: To attach a network interface to an instance with multiple network cards** The following ``attach-network-interface`` example attaches the specified network interface to the specified instance and network card. :: aws ec2 attach-network-interface \ --network-interface-id eni-07483b1897541ad83 \ --instance-id i-01234567890abcdef \ --network-card-index 1 \ --device-index 1 Output:: { "AttachmentId": "eni-attach-0fbd7ee87a88cd06c" } For more information, see `Elastic network interfaces <https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/using-eni.html>`__ in the *Amazon EC2 User Guide*.