Google.com和clients1.google.com/generate_204-Google.comandclients1.google.com/generate_204

24  

Like Snukker said, clients1.google.com is where the search suggestions come from. My guess is that they make a request to force clients1.google.com into your DNS cache before you need it, so you will have less latency on the first "real" request.

就像Snukker说的，clients1.google.com是搜索建议的来源。我的猜测是，在你需要它之前，他们会请求将clients1.google.com强制到你的DNS缓存中，这样你在第一个“真实”请求上的延迟就会减少。

Google Chrome already does that for any links on a page, and (I think) when you type an address in the location bar. This seems like a way to get all browsers to do the same thing.

谷歌Chrome已经为页面上的任何链接做了这样的操作，并且(我认为)当你在地址栏中键入地址时。这似乎是一种让所有浏览器都做同样事情的方法。

33  

I found this old Thread while google'ing for generate_204 as Android seems to use this to determine if the wlan is open (response 204 is received) closed (no response at all) or blocked (redirect to captive portal is present). In that case a notification is shown that a log-in to WiFi is required...

我在谷歌'ing的generate_204中发现了这个旧的线程，因为Android似乎用它来确定wlan是否打开(响应204被接收)关闭(没有响应)或阻塞(重定向到被捕获的门户)。在这种情况下，通知会显示登录到WiFi是必需的…

15  

In the event that Chrome detects SSL connection timeouts, certificate errors, or other network issues that might be caused by a captive portal (a hotel's WiFi network, for instance), Chrome will make a COOKIEless request to http://www.gstatic.com/generate_204 and check the response code. If that request is redirected, Chrome will open the redirect target in a new tab on the assumption that it's a login page. Requests to the captive portal detection page are not logged.

如果Chrome检测到SSL连接超时、证书错误或其他网络问题(比如酒店的WiFi网络)，Chrome将对http://www.gstatic.com/generate_204进行无COOKIE的请求，并检查响应代码。如果这个请求被重定向，Chrome将在一个新的标签页上打开一个重定向目标，假设它是一个登录页面。对被捕获的门户检测页面的请求没有被记录。

Font: Google Chrome Privacy Whitepaper

字体:谷歌Chrome隐私白皮书。

9  

Google is using this to detect whether the device is online or in captive portal.

谷歌使用它来检测设备是在线的还是被捕获的门户。

Shill, the connection manager for Chromium OS, attempts to detect services that are within a captive portal whenever a service transitions to the ready state. This determination of being in a captive portal or being online is done by attempting to retrieve the webpage http://clients3.google.com/generate_204. This well known URL is known to return an empty page with an HTTP status 204. If for any reason the web page is not returned, or an HTTP response other than 204 is received, then shill marks the service as being in the portal state.

当服务转换到就绪状态时，Chromium OS的连接管理器Shill尝试检测在一个被捕获的门户内的服务。通过尝试检索网页http://clients3.google.com/generate_204，可以确定在被捕获的门户网站或在线状态。众所周知，这个众所周知的URL返回一个带有HTTP状态204的空页面。如果由于任何原因，web页面没有返回，或者接收到超过204的HTTP响应，则shill将服务标记为处于门户状态。

Here is the relevant explanation from the Google Chrome Privacy Whitepaper:

以下是谷歌Chrome隐私白皮书的相关说明:

In the event that Chrome detects SSL connection timeouts, certificate errors, or other network issues that might be caused by a captive portal (a hotel's WiFi network, for instance), Chrome will make a COOKIEless request to http://www.gstatic.com/generate_204 and check the response code. If that request is redirected, Chrome will open the redirect target in a new tab on the assumption that it's a login page. Requests to the captive portal detection page are not logged.

如果Chrome检测到SSL连接超时、证书错误或其他网络问题(比如酒店的WiFi网络)，Chrome将对http://www.gstatic.com/generate_204进行无COOKIE的请求，并检查响应代码。如果这个请求被重定向，Chrome将在一个新的标签页上打开一个重定向目标，假设它是一个登录页面。对被捕获的门户检测页面的请求没有被记录。

More info: http://www.chromium.org/chromium-os/chromiumos-design-docs/network-portal-detection

更多信息:http://www.chromium.org/chromium-os/chromiumos-design-docs/network-portal-detection。

5  

204 responses are sometimes used in AJAX to track clicks and page activity. In this case, the only information being passed to the server in the get request is a COOKIE and not specific information in request parameters, so this doesn't seem to be the case here.

在AJAX中，有时会使用204个响应来跟踪单击和页面活动。在这种情况下，在get请求中传递给服务器的唯一信息是一个COOKIE，而不是请求参数中的特定信息，所以这里似乎不是这样。

It seems that clients1.google.com is the server behind google search suggestions. When you visit http://www.google.com, the COOKIE is passed to http://clients1.google.com/generate_204. Perhaps this is to start up some kind of session on the server? Whatever the use, I doubt it's a very standard use.

看起来，clients1.google.com是谷歌搜索建议背后的服务器。访问http://www.google.com时，COOKIE被传递给http://clients1.google.com/generate_204。也许这是在服务器上启动某种会话?无论使用什么，我怀疑这是一个非常标准的用法。

3  

This documents explains:

本文件解释:

http://docs.lib.purdue.edu/cgi/viewcontent.cgi?article=1417&cOntext=ecetr&sei-redir=1

http://docs.lib.purdue.edu/cgi/viewcontent.cgi?article=1417&cOntext=ecetr&sei-redir=1

(Search for generate204)

(寻找generate204)

Relevant section:

相关部门:

Among the different objects, a Javascript function triggers a generate204 request sent to the video server that is supposed to serve the video. This starts the video prefetch, which has two main goals: first, it forces the client to perform the DNS resolution of the video server name. Second, it forces the client to open a TCP connection toward the video server. Both help to speed-up the video download phase.

在不同的对象中，一个Javascript函数会触发一个generate204请求发送到该视频服务器，该服务器应该为视频服务。这将启动视频预取，它有两个主要目标:首先，它强制客户端执行视频服务器名称的DNS解析。其次，它强制客户端打开与视频服务器的TCP连接。两者都有助于加速视频下载阶段。

In addition, the generate204 request has exactly the same format and options of the real video download request, so that the video server is eventually warned that a client will possibly download that video very soon. Note that the video server replies with a 204 No Content response, as implied by the command, and no video content is downloaded so far.

另外，generate204请求与实际视频下载请求的格式和选项完全相同，因此视频服务器最终会发出警告，客户机可能很快就会下载该视频。注意，视频服务器响应的是一个204，没有内容响应，这是由命令所暗示的，而且到目前为止还没有下载视频内容。

2  

I found this blog post which explains that it's used to record clicks. Without official word from Google it could be used any number of things.

我发现这篇博文解释了它是用来记录点击量的。没有谷歌的官方消息，它可以使用任何数量的东西。

http://mark.koli.ch/2009/03/howto-configure-apache-to-return-a-http-204-no-content-for-ajax.html

http://mark.koli.ch/2009/03/howto -配置- apache - -返回- http - 204 -不-内容- - - - - - - ajax。

2  

Many applications access this URL to determine if they have a connection that only leads to a captive portal.

许多应用程序访问这个URL以确定它们是否有连接，而这些连接只会导致被捕获的门户。

The idea is that any captive portal thinks this is a "normal" website, and then redirects you to its portal site, which is returned with a status 200. If an application tries to access any normal website, it is confronted with a totally unexpected response and may have problems figuring out what's wrong. However, with this URL it's easy: If you get status 200, you are inside a captive portal, and you can tell your user to do something about it (usually either log in to the portal using a browser, or turn WiFi off and rely on 3G, if they are using a phone). If you get status 204, you got connected to Google, so your application is actually connected to the internet.

这个想法是，任何被囚禁的门户网站都认为这是一个“正常”的网站，然后将你重定向到它的门户网站，它的返回状态为200。如果一个应用程序试图访问任何正常的网站，它将面对一个完全出乎意料的响应，并且可能会发现问题。然而,这个URL很简单:如果你得到地位200年,你正在在一个被门户网站,你可以告诉你的用户做点什么(通常要么使用浏览器登录到门户,或者关闭WiFi和依靠3 g,如果他们使用的是电话)。如果你得到状态204，你就会连接到谷歌，所以你的应用程序实际上是连接到互联网上的。

Microsoft and Apple use a slightly different approach; they both have some URLs that return a very specific short text message with a status 200, so instead of accessing the Google url you can for example go to "captive.apple.com" and check for status 200 with data = "Success" and nothing else. If you get status 200 and not exactly that data then you are again in a captive portal.

微软和苹果的做法略有不同;它们都有一些url，它们返回一个非常特定的短文本消息，其中有一个状态200，因此，您可以访问“captive.apple.com”，而不是访问谷歌url，并检查状态为200的数据=“成功”，其他什么都没有。如果你获得了状态200，而不是确切的数据，那么你将再次进入一个被囚禁的门户。

1  

with the massive remit by google to stop both spam and the scraping of their search database, I believe that this is part of the effort to track bots etc.

通过谷歌的大量工作来阻止垃圾邮件和搜索数据库的抓取，我相信这是追踪机器人的努力的一部分。

some simple anti bot pseudo could go like this.

一些简单的反机器人可以这样做。

On GET (google.*) Save RemoteEndPoint
{
    If RemoteEndPoint GETs (clients1.google.com/generate_204) Then
        Set botAlert_stage1 = false;
    Else
        Set botAlert_stage1 = true;
    End If
}

I also believe that the latest google frontpage 'theme' is also a new tool to help with the anti spam/bot activity.

我还认为最新的谷歌frontpage“主题”也是一个新的工具来帮助反垃圾邮件/bot活动。

** NOTE ** ipv6.google.com also includes this measure.

也包括这一措施。

Just my unfounded unproofed two 2p.

只是我的毫无根据的两个2p。

0  

The generate 204 might be dynamically loading the suggestions of search criteria. AS i can see from my load test script, this is seemingly responsible for every server call each time the user types into the text box

生成的204可能会动态加载搜索条件的建议。从我的负载测试脚本中可以看到，这似乎是每一次服务器调用用户类型进入文本框时的责任。

-1  

Well i have been looking at this for a few times and resulted that Google logs referer's where they come from first time visiting the google.com for ex; tracking with Google Chrome i have a 90% guess that its for Logging Referers, maybe User-Agent statistics well known when Google release its list of standards of browser usage:

我已经看了好几次了，结果是谷歌记录了referer他们是第一次访问Google。com的时候;在谷歌Chrome的跟踪中，我有90%的猜测是用于登录的用户，也许是用户代理统计数据，当谷歌发布浏览器使用标准列表时，我们就知道了:

• Request URL: http://clients1.google.se/generate_204

  请求URL:http://clients1.google.se/generate_204

• Request Method: GET

  请求方法:

• Status Code: 204 No Content

  状态代码:204无内容。

Response Headers

响应头

• Content-Length: 0
• 内容长度:0
• Content-Type: text/html
• 内容类型:text / html
• Date: Fri, 21 May 2010 17:06:24 GMT
• 日期:2010年5月21日星期五17:06:24
• Server: GFE/2.0
• 服务器:GFE / 2.0

Here "Referer" under "^Request Headers" shows Googles statistics that many folks come from Microsoft.com, also parsing out the word "Windows 7" to help me focus on Windows 7 in my up-following searches that session

在“Request Headers”下的“Referer”显示了google的统计数据，很多人来自Microsoft.com，也分析了“Windows 7”这个词，以帮助我在接下来的搜索中关注Windows 7。

//Steven

/ /史蒂文