const
  ANY_SIZE = 1;
  
type

  MIB_IPADDRROW = record
    dwAddr: LongInt;
    dwIndex: LongInt;
    dwMask: LongInt;
    dwBCastAddr: LongInt;
    dwReasmSize: LongInt;
    unused1: word;
    unused2: word;
  end;

  MIB_IPADDRTABLE = record
    dwNumEntries: LongInt;
    table: array [1 .. ANY_SIZE] of MIB_IPADDRROW;
  end;

  TMIBIpAddrTable = MIB_IPADDRTABLE;
  PMIBIpAddrTable = ^TMIBIpAddrTable;


function GetNetworkAdapters(out AAdapters: TNetworkAdapterInfos): Boolean;
var
  pIfTable: PMIBIfTable;
  pIpTable: PMIBIpAddrTable;
  ifTableSize, ipTableSize: LongInt;
  CurrentAdapter: TNetworkAdapterInfo;
  MacAddress: string;
  i, j, k: Integer;
  sAddr, sMask: in_addr;
  IPAddresses, IPMasks: TDictionary<Integer, AnsiString>;
  IPString: AnsiString;
begin
  IPAddresses := TDictionary<Integer, AnsiString>.Create;
  try
    IPMasks := TDictionary<Integer, AnsiString>.Create;
    try
      ipTableSize := SizeOf(TMIBIpAddrTable);
      GetMem(pIpTable, ipTableSize);
      if GetIpAddrTable(pIpTable, ipTableSize, False) = ERROR_INSUFFICIENT_BUFFER then
      begin
        FreeMem(pIpTable, SizeOf(TMIBIpAddrTable));
        GetMem(pIpTable, ipTableSize);
      end;
      try
        if GetIpAddrTable(pIpTable, ipTableSize, False) = NO_ERROR then
        begin
          for k := 1 to pIpTable^.dwNumEntries do
          begin
            sAddr.S_addr := pIpTable^.table[k].dwAddr;
            sMask.S_addr := pIpTable^.table[k].dwMask;
            if not IPAddresses.ContainsKey(pIpTable^.table[k].dwIndex) then
              IPAddresses.Add(pIpTable^.table[k].dwIndex, inet_ntoa(sAddr));
            if not IPMasks.ContainsKey(pIpTable^.table[k].dwIndex) then
              IPMasks.Add(pIpTable^.table[k].dwIndex, inet_ntoa(sMask));
          end;
        end;
      finally
        if Assigned(pIpTable) then
          FreeMem(pIpTable, ipTableSize);
      end;

...

end;