CloudXNSQQMXCNAME
MXCNAMEMXCNAME
CNAMETTL MXCNAME
DNSCNAMEcacheCNAMEdigMX
CNAMEMXCNAMEMX
CNAMEMXCNAMEDNSSECRRSIGNSECMXANS
CloudXNSDNS
CloudXNSCNAMELINKCloudXNSMXCNAME
wwwCNAMECDN@MXLINKwwwLINK
dig
CloudXNS
20152@CDNDDOSCC
RFC 1034http://tools.ietf.org/pdf/rfc1034
http://download.csdn.net/detail/weicq2000/4627738