anchor.diff:  
   -ifdef(TEST).
   -include_lib("eunit/include/eunit.hrl").
  --define(TEST_AND_DEV, true).
  +-define(TEST_OR_DEV, true).
   -endif.
   
   -ifdef(DEV).
  --define(TEST_AND_DEV, true).
  +-define(TEST_OR_DEV, true).
   -endif.
   
   %% eg. ipneigh_replace(Pid, {44,128,0,1}, {16#70,16#b3,16#d5,16#80,16#00,16#03}, "vtep1024").
   ipneigh_replace(Pid, Dst, Lladdr, Ifname) ->
     Attr = [{dst, Dst}, {lladdr, Lladdr}],
  +  Ifindex = if_nametoindex(Ifname),
     Neigh = {
       _Family = inet,
  -    _Ifindex = if_nametoindex(Ifname),
  +    _Ifindex = Ifindex,
       _State = ?NUD_PERMANENT, 
       _Flags = 0, 
       _NdmType = 0,
  
positive.code: %% ipaddr_add(Pid, {44,128,0,1}, 32, "vtep1024"). 
  ipaddr_replace(Pid, IP, PrefixLen, Ifname) ->
   Attr = [{local, IP},{address, IP}],
   Msg = {
     _Family = inet, 
     _PrefixLen = PrefixLen, 
     _Flags = 0, 
     _Scope = 0, 
     _Ifindex = if_nametoindex(Ifname), 
     Attr},
   netlink_request(Pid, newaddr, [create, replace], Msg). 
  
  -ifdef(TEST_AND_DEV).
  netlink_request(_Pid, getlink, _Flags, _Msg) ->
      {error, 1, ""};
  netlink_request(_Pid, Type, Flags, Msg) ->
  
negative.code: %% eg. bridge_fdb_replace(Pid, {192,168,65,91}, {16#70,16#b3,16#d5,16#80,16#00,16#03}, "vtep1024").
  bridge_fdb_replace(Pid, Dst, Lladdr, Ifname) ->
    Attr = [{dst, Dst}, {lladdr, Lladdr}],
    State = ?NUD_PERMANENT bor ?NUD_NOARP,
    Ifindex = if_nametoindex(Ifname),
    Neigh = {
      _Family = bridge,
      _Ifindex = Ifindex,
      _State = State,
      _Flags = 2,  %% NTF_SELF  
      _NdmType = 0,
      Attr},
  