蓝天博客

在WordPress发布文章中有提示:这篇文章接收trackbacks 和 pingbacks，这个勾选是什么意思呢？

 

大多数网志软件都能让读者添加网志评论。但更常见的做法是让读者在其自己的网志添加一个入口回链到原来的帖子。博客们（Bloggers）都乐于跟踪连接发生的时间以便新读者能理解整个会话内容。

所谓referrer是一个外部站点，用户单击该站点上一个超链接便可以到达你的网站。许多网志引擎当读者导航到你的网志的某个入口时都能自动保持跟踪。大多数引擎都会在网志入口底部显示一个referrers清单，以便读者能往回导航到referrer的站点，并清楚他们关于该入口要说些什么，这基于一个假设，那就是如果他们链接到它，可能就此会写些什么。referrer存在的问题是必须要有这个假设才成立——没有足够的信息说明是否引用的页面事实上包含有关信息。实际上，垃圾信息的发布者为了营销企图已经利用了这个漏洞来重定向读者。

Trackback和pingback同一个规范，被用来弥补上述问题的方案。使用trackback和pingback，其他博客们能自动发送一个ping到你的网志以明确表示他们已经写了一个引用特定帖子的入口。

这种类型的反链允许你的网志以更明显的方式显示所有评论的清单。当今大多数网志软件支持所有这些技术。参见TrackBack Technical Specification和Pingback 1.0。

以下内容摘自Wordpress官方网站：

Trackbacks

Trackbacks were originally developed by SixApart, creators of the MovableType blog package. SixApart has a good introduction to trackbacks:

In a nutshell, TrackBack was designed to provide a method of notification between websites: it is a method of person A saying to person B, "This is something you may be interested in." To do that, person A sends a TrackBack ping to person B.

A better explanation is this:

• Person A writes something on their blog.
• Person B wants to comment on Person A’s blog, but wants her own readers to see what she had to say, and be able to comment on her own blog
• Person B posts on her own blog and sends a trackback to Person A’s blog
• Person A’s blog receives the trackback, and displays it as a comment to the original post. This comment contains a link to Person B’s post

The idea here is that more people are introduced to the conversation (both Person A’s and Person B’s readers can follow links to the other’s post), and that there is a level of authenticity to the trackback comments because they originated from another weblog. Unfortunately, there is no actual verification performed on the incoming trackback, and indeed they can even be faked.

Most trackbacks send to Person A only a small portion (called an "excerpt") of what Person B had to say. This is meant to act as a "teaser", letting Person A (and his readers) see some of what Person B had to say, and encouraging them all to click over to Person B’s site to read the rest (and possibly comment).

Person B’s trackback to Person A’s blog generally gets posted along with all the comments. This means that Person A can edit the contents of the trackback on his own server, which means that the whole idea of "authenticity" isn’t really solved. (Note: Person A can only edit the contents of the trackback on his own site. He cannot edit the post on Person B’s site that sent the trackback.)

SixApart has published an official trackback specification.

Pingbacks

Pingbacks were designed to solve some of the problems that people saw with trackbacks. The official pingback documentation makes pingbacks sound an awful lot like trackbacks:

For example, Yvonne writes an interesting article on her Web log. Kathleen reads Yvonne’s article and comments about it, linking back to Yvonne’s original post. Using pingback, Kathleen’s software can automatically notify Yvonne that her post has been linked to, and Yvonne’s software can then include this information on her site.

There are three significant differences between pingbacks and trackbacks, though.

1. Pingbacks and trackbacks use drastically different communication technologies (XML-RPC and HTTP POST, respectively).
2. Pingbacks support auto-discovery where the software automatically finds out the links in a post, and automatically tries to pingback those URLs, while trackbacks must be done manually by entering the trackback URL that the trackback should be sent to.
3. Pingbacks do not send any content.

The best way to think about pingbacks is as remote comments:

• Person A posts something on his blog.
• Person B posts on her own blog, linking to Person A’s post. This automatically sends a pingback to Person A when both have pingback enabled blogs.
• Person A’s blog receives the pingback, then automatically goes to Person B’s post to confirm that the pingback did, in fact, originate there.

The pingback is generally displayed on Person A’s blog as simply a link to Person B’s post. In this way, all editorial control over posts rests exclusively with the individual authors (unlike the trackback excerpt, which can be edited by the trackback recipient). The automatic verification process introduces a level of authenticity, making it harder to fake a pingback.

Some feel that trackbacks are superior because readers of Person A’s blog can at least see some of what Person B has to say, and then decide if they want to read more (and therefore click over to Person B’s blog). Others feel that pingbacks are superior because they create a verifiable connection between posts.

Verifying Pingbacks and Trackbacks

Comments on blogs are often criticized as lacking authority, since anyone can post anything using any name they like: there’s no verification process to ensure that the person is who they claim to be. Trackbacks and Pingbacks both aim to provide some verification to blog commenting.