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


tos value chain [rule-params]


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


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

The value can be an integer number (decimal or hexadecimal) or one of the descriptive values accepted by iptables(8) (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) 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) for more details.

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


# 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
 tos Maximize-Throughput FORWARD proto tcp dport 25 dst