code: def _do_add_floating_ip_asr1k(self, floating_ip, fixed_ip, vrf,
                                    ex_gw_port):
          
          vlan = ex_gw_port['hosting_info']['segmentation_id']
          hsrp_grp = ex_gw_port[ha.HA_INFO]['group']
  
          LOG.debug("add floating_ip: %(fip)s, fixed_ip: %(fixed_ip)s, "
                    "vrf: %(vrf)s, ex_gw_port: %(port)s",
                    {'fip': floating_ip, 'fixed_ip': fixed_ip, 'vrf': vrf,
                     'port': ex_gw_port})
  
          confstr = (asr1k_snippets.SET_STATIC_SRC_TRL_NO_VRF_MATCH %
              (fixed_ip, floating_ip, vrf, hsrp_grp, vlan))
          self._edit_running_config(confstr, 'SET_STATIC_SRC_TRL_NO_VRF_MATCH')
docs: To implement a floating ip, an ip static nat is configured in the
          underlying router ex_gw_port contains data to derive the vlan
          associated with related subnet for the fixed ip.  The vlan in turn
          is applied to the redundancy parameter for setting the IP NAT.