Google提供了公共递归DNS服务器，全世界都知道了吧？

8.8.8.8
8.8.4.4


买的以前DoD的IP段。恩～～～差一点就可以劫持8.7.198.45所有流量了。。。可惜啊。。。

支持DNSSec。非常好。。。。。

免费归免费，但是还是会log不少信息的。。

Google旗下服务能根据CDN智能解析。。。很好～～～～比OpenDNS那个废品HTTP劫持再跳转好多了。而且不会劫持NXDOMAIN和SERVFAIL：

Google Public DNS complies with the DNS standards and gives the user the exact response his or her computer expects without performing any blocking, filtering, or redirection that may hamper a user's browsing experience.

其他CDN会尽量做到智能解析，因为Google全球都有数据中心。。。

Google Public DNS is hosted in data centers worldwide, and uses anycast routing to send users to the geographically closest data center.
Note, however, that because nameservers geolocate according to the resolver's IP address rather than the user's, Google Public DNS has the same limitations as other open DNS services: that is, the server to which a user is referred might be farther away than one to which a local DNS provider would have referred. This could cause a slower browsing experience for certain sites.

这里提一下，HN上有人人披露了一个新IP：4.3.2.1

$ whois 4.3.2.1
Level 3 Communications, Inc. LVLT-ORG-4-8 (NET-4-0-0-0-1)
                                  4.0.0.0 - 4.255.255.255
Google Incorporated LVLT-GOOGL-1-4-3-2 (NET-4-3-2-0-1)
                                  4.3.2.0 - 4.3.2.255

$ nslookup g.cn 4.3.2.1
Server:  any-in-0201.1e100.net
Address:  4.3.2.1

Non-authoritative answer:
Name:    g.cn
Addresses:  203.208.39.104, 203.208.39.99

如果那两个被OOXX了就用这个吧。。。。

问了下大牛，貌似这个prefetch和BIND的缓存不同就是TTL过期之后，再服务器update一次，而不是清空缓存。提高一点效率吧。。。但是遇到Fast Flux估计Google就SB了。

Google这次破天荒的提供了电话服务。很令人震惊。。。

Google Public DNS telephone support
* 877-590-4367 in the U.S.
* 770-200-1201 outside the U.S

有人试了下，自动问答。FT！

还就就是终于知道 4.2.2.1 - 4.2.2.6 那个DNS是属于Level 3 Communications的。