def ec2_eni_eni_id(self, lookup, default=None):
    """
    Args:
      lookup: the description of the Elastic Network Interface (ENI) to look up
      default: the optional value to return if lookup failed; returns None if not set
    Returns:
      The ID of the first ENI found with a description matching 'lookup' or default/None if no match found
    """
    enis = EFAwsResolver.__CLIENTS["ec2"].describe_network_interfaces(Filters=[{
      'Name': 'description',
      'Values': [lookup]
    }])
    if len(enis.get("NetworkInterfaces")) > 0:
      return enis["NetworkInterfaces"][0]["NetworkInterfaceId"]
    else:
      return default