'Get existing info'

def get_existing(self):

    dldp_conf = dict()
    dldp_conf['interface'] = self.interface
    dldp_conf['enable'] = self.dldp_intf_conf.get('dldpEnable', None)
    dldp_conf['mode_enable'] = self.dldp_intf_conf.get('dldpCompatibleEnable', None)
    dldp_conf['local_mac'] = self.dldp_intf_conf.get('dldpLocalMac', None)
    dldp_conf['reset'] = 'disable'
    self.existing = copy.deepcopy(dldp_conf)
