语法
dig [@server] [-b address] [-c class] [-f filename] [-k filename] [ -n ][-p port#] [-t type] [-x addr] [-y name:key] [name] [type] [class] [queryopt...]
dig @202.99.224.8 www.12530.com
nslookup -qt=ns 12530.com
nslookup -norecurse www.12530.com 202.99.224.8
