---
name: "firehol-tos"
section: "5"
platform: "linux"
package: "firehol-doc"
version: "3.1.8+ds-1"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/firehol-tos"
---

# firehol-tos(5)

set the Type of Service (TOS) of packets

## NAME

firehol-tos - set the Type of Service (TOS) of packets

## SYNOPSIS

tos *value* *chain* \[*rule-params*\]

## DESCRIPTION

The `tos` helper command sets the Type of Service (TOS) field in packet headers.

**Note**

There is also a `tos` parameter which allows matching TOS values within individual rules (see [firehol-params(5)](/firehol-params/5.md)).

The *value* can be an integer number (decimal or hexadecimal) or one of the descriptive values accepted by [iptables(8)](/iptables/8.md) (run `iptables -j TOS --help` for a list).

The *chain* will be used to find traffic to mark. It can be any of the [iptables(8)](/iptables/8.md) built in chains belonging to the `mangle` table. The chain names are: INPUT, FORWARD, OUTPUT, PREROUTING and POSTROUTING. These names are case-sensitive.

The *rule-params* define a set of rule parameters to match the traffic that is to be marked within the chosen chain. See [firehol-params(5)](/firehol-params/5.md) for more details.

Any `tos` commands will affect all traffic matched. They must be declared before the first `router` or `interface`.

## EXAMPLES

-

  ```
   # set TOS to 16, packets sent by the local machine
   tos 16 OUTPUT
   # set TOS to 0x10 (16), packets routed by the local machine
   tos 0x10 FORWARD
   # set TOS to Maximize-Throughput (8), packets routed by the local
   #              machine, destined for port TCP/25 of 198.51.100.1
   tos Maximize-Throughput FORWARD proto tcp dport 25 dst 198.51.100.1
  ```

## SEE ALSO

- •

  [firehol(1)](/firehol/1.md) - FireHOL program

- •

  [firehol.conf(5)](/firehol.conf/5.md) - FireHOL configuration

- •

  [firehol-params(5)](/firehol-params/5.md) - optional rule parameters

- •

  [firehol-tosfix(5)](/firehol-tosfix/5.md) - tosfix config helper

- •

  [iptables(8)](/iptables/8.md) ⟨http://ipset.netfilter.org/iptables.man.html⟩\\c  - administration tool for IPv4 firewalls

- •

  [ip6tables(8)](/ip6tables/8.md) ⟨http://ipset.netfilter.org/ip6tables.man.html⟩\\c  - administration tool for IPv6 firewalls

- •

  FireHOL Website ⟨http://firehol.org/⟩\\c

- •

  FireHOL Online PDF Manual ⟨http://firehol.org/firehol-manual.pdf⟩\\c

- •

  FireHOL Online Documentation ⟨http://firehol.org/documentation/⟩\\c

## AUTHORS

FireHOL Team.