# Page Not Found

The URL `di-2-zhang-an-zhuang-freebsd/di-2.1-install-pre` does not exist. This page may have been moved, renamed, or deleted.

## Suggested Pages

You may be looking for one of the following:
- [2.3 安装故障排除](https://book.bsdcn.org/di-2-zhang-freebsd-an-zhuang-ji-chu/di-2.3-jie-an-zhuang-gu-zhang-pai-chu.md)
- [17.3 ipfirewall（IPFW）](https://book.bsdcn.org/di-17-zhang-fang-huo-qiang/di-17.3-jie-ipfirewall-ipfw.md)
- [4.6 Shell 配置](https://book.bsdcn.org/di-4-zhang-freebsd-ji-chu/di-4.6-jie-shell-pei-zhi.md)
- [9.1 ZFS 概述](https://book.bsdcn.org/di-9-zhang-zfs-wen-jian-xi-tong/di-9.1-jie-zfs-gai-shu.md)
- [4.5 Shell 基础](https://book.bsdcn.org/di-4-zhang-freebsd-ji-chu/di-4.5-jie-shell-ji-chu.md)

## How to find the correct page

If the exact page cannot be found, you can still retrieve the information using the documentation query interface.

### Option 1 — Ask a question (recommended)

Perform an HTTP GET request on the documentation index with the `ask` parameter:

```
GET https://book.bsdcn.org/di-2-zhang-freebsd-an-zhuang-ji-chu/di-2.3-jie-an-zhuang-gu-zhang-pai-chu.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

### Option 2 — Browse the documentation index

Full index: https://book.bsdcn.org/sitemap.md

Use this to discover valid page paths or navigate the documentation structure.

### Option 3 — Retrieve the full documentation corpus

Full export: https://book.bsdcn.org/llms-full.txt

Use this to access all content at once and perform your own parsing or retrieval. It will be more expensive.

## Tips for requesting documentation

Prefer `.md` URLs for structured content, append `.md` to URLs (e.g., `/di-2-zhang-freebsd-an-zhuang-ji-chu/di-2.3-jie-an-zhuang-gu-zhang-pai-chu.md`).

You may also use `Accept: text/markdown` header for content negotiation.