host    oar         oar_ro            127.0.0.1          255.255.255.255    md5
  host    oar         oar               127.0.0.1          255.255.255.255    md5
  host    oar         oar_ro            <frontend ip>      <netmask>    md5
  host    oar         oar               <frontend ip>      <netmask>    md5