> For the complete documentation index, see [llms.txt](https://refabr1k.gitbook.io/oscp/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://refabr1k.gitbook.io/oscp/info-gathering/port-knocking.md).

# Port Knocking

### Nmap TCP Port knock in sequence

```bash
IFS=$(' ')

#knock in sequence
for i in 324 125 235;do nmap -Pn -p $i --host-timeout 201 --max-retries 0 10.10.10.23; done

#after knock check if port is opened
nmap -p 22 10.10.10.23
```