http://www.google.com.vn/url?sa=t&rct=j&q&esrc=s&source=web&cd=3&sqi=2&ved=0CGgQFjAC&url=http%3A%2F%2Fuet.vnu.edu.vn%2Ftltk%2FLearning%2FFile_PDF%2FCau_truc_dia_chi_Ip_tren_Internet.pdf&ei=MPq-T-_uDem1iQfKqcSkCg&usg=AFQjCNFFyAvd8wHw0q4gPqdSPGeQ4ntBRg&sig2=vviJxEVHS79ByN0TcIPQ8A