def METHOD_NAME():
  ipr = IPRoute()
  defaultRouteAttrs = dict(ipr.get_default_routes(family=socket.AF_INET, table=254)[0]['attrs'])
  link = ipr.get_links(defaultRouteAttrs['RTA_OIF'])
  linkAttrs = dict(link[0]['attrs'])
  return linkAttrs['IFLA_IFNAME']