由dns.he.net提供的免费dns域名解析服务，支持A, AAAA, CNAME, MX, NS, TXT, SRV, PTR记录，支持纯域名ns记录，支持ru域名，不支持 co.cc二级域名，每个账号可以绑定25个域名，其dns服务器有5个，分别是ns1.he.net,ns2.he.net,ns3.he.net,ns4.he.net,ns5.he.net。
Dualstack: Supports queries via both IPv4 and native IPv6.
Support for A, AAAA, CNAME, MX, NS, TXT, SRV, and PTR records.
Smart mode IPv4 and IPv6 reverse zones simplifies reverse zones.
Multiple reverse zone formats: Standard, RFC 4183, RFC 2317, DeGroot.
5 geographically diverse servers.
Sanity checking for delegation for both forward and reverse zones.
Basic syntax checking for fields.
Multiple domains per account.
2010年7月3日
