more about multiple hubs here
Also, like Brockster said, it's possible that you are either on a domestic airport, thus you have no international flights, or you are based on an international airport, and thus have no domestic flights. A good example of this are the 2 airports in Tokyo, Narita and Haneda. Narita is International, and Haneda domestic. And the thing that causes mistakes here, is the fact, that Haneda has the most passengers going through/year in Japan, or is it even in whole Asia? Anyways, Japan domestic flights transport a huge amount of passengers each day.