---
name: "queso.conf"
section: "5"
platform: "linux"
package: "queso"
version: "0.980922b-3"
release: "Debian 3.0 (Woody)"
platforms: ["linux"]
url: "https://new.carta.tech/queso.conf"
---

# queso.conf(5)

Database of operating systems and their TCP implementation characteristics.

## NAME

**queso.conf** – Database of operating systems and their TCP implementation characteristics.

## DESCRIPTION

The file */etc/queso.conf* contains a list of operating systems followed by the description of the response they give upon receiving certain TCP datagrams.

## LAYOUT

Lines beginning with; are considered comments and are ignored.

Lines beginning with \* denote the start of the description of an operating system. Lines which begin with \* are followed by the name of the operating system. This line is printed verbatim if it is matched. Up to seven lines of the following format may follow:

*n* *s* *a* *w* *f*

- *n*

  A number ranging from 0 to 6. Indicated the type of probe that was sent.

  - 0

    SYN

  - 1

    SYN+ACK

  - 2

    FIN

  - 3

    FIN+ACK

  - 4

    SYN+FIN

  - 5

    PSH

  - 6

    SYN+XXX+YYY

- *s*

  Indicates whether the sequence number matches or not. Can be 1 or 0.

- *a*

  Indicates whether the acknowledgement number matches or not. Can be 1 or 0.

- *w*

  Indicates whether the window size is different or not. Can be 1 or 0, or a hexadecimal number indicating which window size to expect on the response packet.

- *f*

  Indicates which flags are set on the response packet.

  - S

    SYN

  - F

    FIN

  - R

    RST

  - A

    ACK

  - P

    PSH

  - U

    URG

  - X

    - Y

    To indicate that a host does not respond at all to a certain type of probe, specify the following line:

*n* - - - -

## EXAMPLE

```
;The following block matches a generic Linux host.
* Linux 2.1.xx/2.2.xx
0 1 1 7FB8 SA
1 0 0 0 R
2 - - - -
3 0 0 0 R
4 1 1 7FB8 SA
5 - - - -
6 1 1 7FB8 SA
```

## FILES

*/etc/queso.conf*

## SEE ALSO

[queso(8)](/queso/8.md)

## AUTHOR

This manual page was written by Guus Sliepen ⟨guus@sliepen.warande.net⟩ for the Debian GNU/Linux system.