> For the complete documentation index, see [llms.txt](https://cajac.gitbook.io/ctf-notes/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://cajac.gitbook.io/ctf-notes/enum/network-discovery/basic-os-fingerprinting.md).

# Basic OS Fingerprinting

## Basic OS fingerprinting

We can do a basic OS fingerprinting with `ping` and check the TTL-value of the response packet

```bash
ping -c 1 $TARGET_IP
```

Since the TTL-value normally differs between different hardware platforms we will have a likely operating system of the target machine.

<table><thead><tr><th width="210">TTL-value of response</th><th></th></tr></thead><tbody><tr><td>&#x3C; 64</td><td>Linux/Unix</td></tr><tr><td>&#x3C; 128</td><td>Windows</td></tr><tr><td>&#x3C; 254</td><td>Cisco devices</td></tr></tbody></table>

## Resources

ping - Linux manual page: <https://man7.org/linux/man-pages/man8/ping.8.html>

Time to live - Wikipedia: <https://en.wikipedia.org/wiki/Time_to_live>