> For the complete documentation index, see [llms.txt](https://alexanderbittner.gitbook.io/pentest-resources/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://alexanderbittner.gitbook.io/pentest-resources/vulnerability-analysis/standard-ports-and-common-services/00-service-unknown.md).

# 00 - Service unknown

If a server is running on a non-default port or the software running is not common, fear not! Here are some techniques:

### Banner grabbing with netcat:

`nc -nv <ip-addr> <port>`