NetProbe 2.0 — 站点连通性诊断探针
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这是什么 / What is this
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NetProbe 是一个由用户主动发起的一次性网站诊断工具。当有人在
https://net-probe.complexmission.com 输入你的域名并点击检测时，本服务会
代其向你的站点发起少量请求。它不是爬虫，不会遍历链接，不会抓取内容，
也不会周期性回访。

NetProbe is an on-demand, user-initiated website diagnostic tool. It fetches
your site only when a human explicitly asks it to. It is not a crawler: it
follows no links, indexes nothing, and never revisits on a schedule.

一次检测会做什么 / What one check does
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  - GET /            读取响应头与 <title>，正文最多读取 512 KB
  - GET /robots.txt
  - 对 80 端口做一次跳转检查
  - 5 次 TLS 握手（1 次取证书链 + 4 次逐版本探测协议支持情况）

合计约 8 次连接，全部在几秒内完成，之后不再有流量。

  - GET /            response headers and <title>; at most 512 KB of body
  - GET /robots.txt
  - one request to port 80 to check the HTTPS redirect
  - 5 TLS handshakes (1 for the chain, 4 to probe TLS 1.0-1.3 support)

About 8 connections in total, all within a few seconds, then nothing more.

如何识别 / How to identify it
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User-Agent: Mozilla/5.0 (compatible; NetProbe/2.0; +https://net-probe.complexmission.com/about)

如何屏蔽 / How to block it
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在 robots.txt 中：

    User-agent: NetProbe
    Disallow: /

或在服务器/WAF 层按上面的 User-Agent 或来源 IP 直接拒绝。我们不会绕过。
Or reject the User-Agent above at your server or WAF. We will not work around it.

联系我们 / Contact us
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https://net-probe.complexmission.com/contact

上面是一个网页表单，留言会实时推送到运维手机上，通常几分钟内就能看到。
这里不放邮箱：UA 会出现在无数访问日志里，写邮箱等于主动投喂爬虫。

That is a web form. Messages are pushed to the operator in real time, so they
are usually seen within minutes. We deliberately do not print an email address
here: this User-Agent ends up in countless access logs, and publishing an
address there just feeds harvesters.

如果本服务给你带来了困扰，请通过上面的表单告诉我们，我们会尽快处理。
If this service is causing you trouble, tell us through the form above.