blocks|key|3897510|text|我所读过的关于DNS的每一次引用都清楚地表明，在执行DNS查找时，尾随点是隐含的，因此是多余的。添加它绝对没有好处。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|entityMap^0^^$0|@$1|2|3|4|5|6|7|C|8|@]|9|@]|A|$]]]|B|$]]

Every reference I've ever read about DNS makes it perfectly clear that when performing a DNS lookup the trailing dot is implied and therefore redundant. There is absolutely no advantage in adding it.

blocks|key|3897486|text|这是直接从维基百科：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3897487|在域名系统中，特别是在DNS区域文件中，使用尾随点指定完全限定的域名。|blockquote|3897488|它从未在DNS区域之外使用，这可能是您从未见过它的原因。但在DNS区域，它有着巨大的意义。那个小点可以打破许多非常重要的东西。|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|H|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|I|8|@]|9|@]|A|$]]|$1|E|3|F|5|6|7|J|8|@]|9|@]|A|$]]]|G|$]]

This is straight from Wikipedia:

<blockquote>
 In the Domain Name System, and most
 notably, in DNS zone files, a fully
 qualified domain name is specified
 with a trailing dot
</blockquote>

It is never used outside of DNS zones, thats probably why you never see it. 
But in DNS zones, it has HUGE significance. That little dot can break a lot of very important things.

blocks|key|5898426|text|因为人们是懒惰的，当给出一个选项时，他们会输入最短的东西。另见no-www.org。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|5898427|如果您不信任您的网络，您可以完全摆脱您的计算机上的任何DNS后缀，并指向其他一些DNS服务器。或者更好地为您信任的某个网络创建一个VPN。|5898428|通常，只有管理员才能向DNS服务器添加记录。如果你的系统管理员想要劫持你的网络请求，有许多其他更有效的方式从他这样做。如果黑帽可以控制您所指向的DNS服务器，它们可能为它们想要的任何域提供任何地址，甚至是有效的完全限定域。根据客户端追加后缀提供名称并不是一种非常有用的攻击。|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|G|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|H|8|@]|9|@]|A|$]]|$1|D|3|E|5|6|7|I|8|@]|9|@]|A|$]]]|F|$]]

Because people are lazy, and will type the shortest thing they can when given an option. See also no-www.org.

If you don't trust your network you could completely get rid of any DNS suffixes on your computer and point at some other DNS servers. Or even better create a VPN to some network you do trust.

Typically only your administrator has the ability to add records to the DNS server. If your sysadmin wants to hijack your web requests there are many other more effective ways from him to do that. If a blackhat can get control of the DNS servers you are pointing at they could possibly serve any address for any domain they want, even the valid fully qualified domain. Serving names depending on the client appending a suffix wouldn't be a very useful attack.

blocks|key|5898547|text|相对名称"www.bankofamerica.com.example.com.“只有那些告诉你的计算机它的域名是"example.com“的人才能利用。这来自DHCP或安装计算机的人员。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|5898548|为了利用这一点，您的DHCP提供商(您的公司或您的ISP)必须在其DNS中创建这些明显可疑的名称。|5898549|在现实中，他们不必费心去攻击你(如果他们想的话)。他们是你的ISP。他们已经控制您的DNS，事实上，他们也控制您的流量。|5898550|通过捕获和重定向您的流量或劫持您的所有DNS请求，它们可以轻松、更可靠地捕获和重定向您的流量，而不仅仅是那些查找古怪的相对名称的请求(比如www.google.com.comcast.net)。一些ISP已经以这种方式“攻击”了他们的客户，他们用自己的广告页面重定向上游DNS提供商的“没有这样的域”错误。|5898551|因此，您无论如何都必须信任它们，所以您也可以信任它们(并验证您的ssl证书！)。|5898552|最后，主机名上的终端点会破坏许多web服务器。例如，如果您转到“http://stackoverflow.com”，堆栈三部曲服务器就会抓狂。|offset|length|entityMap|0|LINK|mutability|MUTABLE|url|http://stackoverflow.com/^0|0|0|0|0|0|W|O|0^^$0|@$1|2|3|4|5|6|7|U|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|V|8|@]|9|@]|A|$]]|$1|D|3|E|5|6|7|W|8|@]|9|@]|A|$]]|$1|F|3|G|5|6|7|X|8|@]|9|@]|A|$]]|$1|H|3|I|5|6|7|Y|8|@]|9|@]|A|$]]|$1|J|3|K|5|6|7|Z|8|@]|9|@$L|10|M|11|1|12]]|A|$]]]|N|$O|$5|P|Q|R|A|$S|T]]]]

The relative name "www.bankofamerica.com.example.com." is only exploitable by those who told your computer that it's domain is "example.com". This comes from either DHCP or by the person who setup the computer.

In order to exploit that, your DHCP provider (your company or your ISP) would have to create these clearly fishy names in their DNS.

In reality, they don't have to bother to do this to attack you (if they wanted to). They're your ISP. They already control your DNS and in fact they control your traffic as well. 

They could just as easily and more reliably capture and redirect your traffic by capturing and redirecting your traffic or hijacking all your DNS requests, not just the ones that look up wacky relative names (such as www.google.com.comcast.net.). Some ISPs already "attack" their customers in this way by redirecting "no such domain" errors from upstream DNS providers with their own advertisement pages. 

So, you have to trust them anyhow, so you may as well trust them (and verify your ssl certificates!).

Lastly, the terminal dot on a hostname will break lots of web servers. For instance, the stack trilogy servers freak out if you go to "<a href="http://stackoverflow.com">http://stackoverflow.com</a>."

blocks|key|3897553|text|如果省略了尾随点，并且您没有搜索路径，这并不重要。但是，当您有搜索路径时，解析器将首先尝试在搜索路径中追加域名并解析它们，如果没有解析，则只尝试名称。当.cs是一个工作的ccTLD时，它被用作一个示例来证明这一点:当您单击host.cs时，它就是host.cs。是回复还是host.cs.dom.ain？|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3897554|尾随点确实很重要，但观察到这一点的情况非常少。|3897555|您可能需要阅读域的“tinyurl”服务来查看搜索路径和尾随点的巧妙使用。|offset|length|entityMap|0|LINK|mutability|MUTABLE|url|http://everythingsysadmin.com/2009/12/a-tinyurl-service-for-your-dom.html^0|0|0|7|D|0^^$0|@$1|2|3|4|5|6|7|O|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|P|8|@]|9|@]|A|$]]|$1|D|3|E|5|6|7|Q|8|@]|9|@$F|R|G|S|1|T]]|A|$]]]|H|$I|$5|J|K|L|A|$M|N]]]]

When the trailing dot is omitted and you do not have a search path, it does not matter. But when you have a search path it does, for the resolver will first try to append the domain names in the search path and resolve them and if unresolved will try the name alone. When .cs was a working ccTLD it was used as an example to demonstrate this: When you pinged host.cs was host.cs. that was replying or host.cs.dom.ain?

The trailing dot does matters, but the situations that one will observe this are very few.

You may want to read <a href="http://everythingsysadmin.com/2009/12/a-tinyurl-service-for-your-dom.html" rel="nofollow noreferrer">A "tinyurl" service for your domain</a> to see a clever use of the search path and the trailing dot.

I recently learned that a fully qualified domain name ends in a dot, e.g. <code>www.microsoft.com.</code>. Why do I almost never see this? We casually toss around <code>www.microsoft.com</code>, a relative domain name, without a second thought.

It's not mere pedantry, because it seems there's a security issue: someone in your network could create <code>www.microsoft.com.example.com.</code> to hijack your requests to <code>www.microsoft.com</code>. Why doesn't the internet community have a tradition of using genuinely fully qualified domain names?

Edit:

Thanks to everyone who answered. I misunderstood when domain suffixes were added.

If I understand correctly: First the application turns your input into a fully qualified domain name, by appending suffixes or just a dot. Then the formal DNS query is sent to a nameserver.

Why no final dot for domain names?

翻译质量差，导致语言生硬或混乱。

没有提供实际的解决方法或示例。

解答不清晰，无法理解或解决问题。

页面排版不美观，阅读体验差。

文章

问答

视频

教程

学习中心

腾讯云实验室

直播

竞赛

腾讯云代码分析专区

腾讯iOA零信任安全管理系统专区

腾讯云架构师技术同盟交流圈

腾讯云数据库专区

腾讯云智能顾问专区

腾讯云原生专区

腾讯混元专区

腾讯云TCE专区

腾讯云Lighthouse专区

腾讯云HAI专区

腾讯云Edgeone专区

腾讯云存储专区

腾讯云智能专区

腾讯轻联专区 

腾讯云开发专区

TAPD专区

腾讯轻量云游戏服专区

EdgeOne AI 安全实战专区

腾讯云最具价值专家

腾讯云架构师技术同盟

腾讯云创作之星

腾讯云开发者先锋

腾讯云代码助手

云原生构建

TAPD 敏捷项目管理

Cloud Studio

SDK中心

API中心

命令行工具

涵盖代码开发、场景应用、自动测试全流程，助你从零构建专属AI助手

一站式MCP教程库，解锁AI应用新玩法

聚焦“写作效率、视觉美观与运行性能”三方面进行全面升级，为您提供更高效、稳定的创作环境

社区富文本&Markdown编辑器全新改版上线，欢迎大家体验!

诚挚邀请您参与本次调研，分享您的真实使用感受与建议。您的反馈至关重要，感谢您的支持与参与！

社区新版编辑器体验调研

最近我了解到，一个完全限定的域名以圆点结尾，例如www.microsoft.com.。为什么我几乎从来没见过这个？我们漫不经心地在www.microsoft.com，一个相对的域名，没有再想一想。这不仅仅是学究，因为似乎存在一个安全问题:您的网络中有人可以创建www.microsoft.com.example.com.来劫持您的请求到www.microsoft.com。为什么互联网社区没有使用真正

问为什么域名没有最后的点？
EN

编辑：

回答 5

Server Fault用户

Server Fault用户

Server Fault用户

社区

活动

圈层

关于

腾讯云开发者

热门产品

热门推荐

更多推荐

问为什么域名没有最后的点？EN

编辑：

回答 5

Server Fault用户

Server Fault用户

Server Fault用户

社区

活动

圈层

关于

腾讯云开发者

热门产品

热门推荐

更多推荐

问为什么域名没有最后的点？
EN