public async Task deleteNetworkInterfaces(string vpcId) { var descResponse = await _ec2Client.DescribeNetworkInterfacesAsync(new DescribeNetworkInterfacesRequest() { Filters = new List <Filter>() { new Filter() { Name = "vpc-id", Values = new List <string>() { vpcId } } } }); foreach (var item in descResponse.NetworkInterfaces) { if (item.Attachment != null && !string.IsNullOrEmpty(item.Attachment.AttachmentId)) { await _ec2Client.DetachNetworkInterfaceAsync(new DetachNetworkInterfaceRequest() { AttachmentId = item.Attachment.AttachmentId, Force = true }); } await _ec2Client.DeleteNetworkInterfaceAsync(new DeleteNetworkInterfaceRequest() { NetworkInterfaceId = item.NetworkInterfaceId }); } }