# Syslog

Leona is able to accept and parse [RFC 5424](https://www.ietf.org/rfc/rfc5424.txt) and [RFC 3164](https://www.ietf.org/rfc/rfc3164.txt) compliant syslog messages and supports TCP transport with both the octet counting or termination character methods. UDP is also supported and the recommended way to send log messages in most architectures.

**Many devices, especially routers and firewalls, do not send RFC compliant syslog messages.** This might result in wrong or completely failed parsing. In that case, you might have to go with a combination of raw/plaintext message inputs that do not attempt to do any parsing and [Extractors](/leona/getting-in/log-sources/gelf.md).

Rule of thumb is that messages forwarded by [rsyslog](https://www.rsyslog.com/) or [syslog-ng](https://github.com/syslog-ng/syslog-ng) are usually parsed flawlessly.

<br>


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://ciusji.gitbook.io/leona/getting-in/log-sources/ingest-logs-manually/syslog.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.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.