作为主机名的顶级域的示例

Question

On Wikipedia 我读到 TLD 也可以是主机名：

However, other top-level domains, particularly country code top-level domains, may indeed have an IP address, and if so, they are also hostnames.

据我了解，这将是一个类似于 http://org/ 的域。当我输入这样的 URL 时，我通常会转到 http://www.org.com/ 之类的内容。有这样的网站的实例吗？

Answer 1

http://dk/就是这样的例子：

LANG=C wget -S http://dk/
--2018-02-27 23:44:23--  http://dk/
Resolving dk (dk)... 193.163.102.58, 2a01:630:0:40::58
Connecting to dk (dk)|193.163.102.58|:80... connected.
HTTP request sent, awaiting response... 
  HTTP/1.1 301 Moved Permanently
  Server: nginx
  Date: Wed, 28 Feb 2018 04:44:24 GMT
  Content-Type: text/html
  Content-Length: 178
  Connection: keep-alive
  Location: https://www.dk-hostmaster.dk/

您在浏览器中观察到的是您的浏览器经验规则，如果第一次直接 DNS 查询失败，它会自动处理 .COM。

如果你想自学，看看https://www.icann.org/en/system/files/files/sac-053-en.pdf :

SSAC calls a domain name that consists of a single label a “dotless domain.” Applicants for new gTLDs who ask the question posed above want to know whether or not a dotless domain would be handled by Internet infrastructure and applications in the same way as other domain names. In this report, the SSAC finds that dotless domains would not always work as expected given current DNS implementation and existing application behavior. In particular, the SSAC finds that the way in which domain names are interpreted in different contexts would lead to unpredictable and unexpected dotless domain behavior.

这也解释了为什么您不会在 gTLD（旧的或新的）中找到这个 "feature"：它被 ICANN 明确禁止（没有很好的技术原因，但主要是在 SiteFinder 惨败之后）。所以您需要查看 ccTLD。

作为主机名的顶级域的示例

Example of a top-level domain that is a hostname

dns

domain-name