cugb.edu.cn                    has IPv4  has IPv6  ::1  (time=0.000133)
ecust.edu.cn                   has IPv4  has IPv6  ::1  (time=0.000089)
edu22.info                     has IPv4  has IPv6  ::1  (time=0.000093)
pega.com                       has IPv4  has IPv6  ::  (time=0.000096)