多项选择题
A.6to4 B.6over4 C.ISATAP D.GRE
A.0.0.0.1 B.0.255.0.1 C.2001:DB8::1 D.2001:DB8:ABCD:FEEF::1
A.2001:DB8::1 and 2001:DB8::2 B.2001:DB8::9 and 2001:DB8::10 C.2001:DB8::10 and 2001:DB8::17 D.2001:DB8::1 and 2001:DB8::18