[NumLock]

Код:

var
  AdapterInfo: PIP_ADAPTER_INFO;
  Next: PIP_ADAPTER_INFO;
  pOutBufLen: ULONG;
  ipstats: MIB_IPSTATS;
  tcpstats: MIB_TCPSTATS;
begin
  pOutBufLen:=0;
  if GetAdaptersInfo(nil, @pOutBufLen)=ERROR_BUFFER_OVERFLOW then
  begin
    AdapterInfo:=GetMemory(pOutBufLen);
    try
      if GetAdaptersInfo(AdapterInfo, @pOutBufLen)=ERROR_SUCCESS then
      begin
        Next:=AdapterInfo;
        while Next<>nil do
        begin
          Memo1.Lines.Add('AdapterName: '+Next^.AdapterName);
          Memo1.Lines.Add('Description: '+Next^.Description);
          Memo1.Lines.Add('IpAddress: '+Next^.IpAddressList.IpAddress);
          Memo1.Lines.Add('');
          Next:=Next^.Next;
        end;
      end;
    finally
      FreeMemory(AdapterInfo);
    end;
  end else ShowMessage(SysErrorMessage(GetLastError));
end;

только что проверил, работает.