dscp config helper: sanewall-dscp

5
sanewall-dscp

sanewall-dscp

set the DSCP field in the packet header

        dscp

           value
           class classid

        chain
        rule-params

## Description

The `dscp` helper command sets the DSCP field in the header of packets traffic, to allow QoS shaping.

There is also a `dscp` parameter which allows matching DSCP values within individual rules (see rule-params).

Set `value` to a decimal or hexadecimal (0xnn) number to set an explicit DSCP value or use `class` `classid` to use an iptables DiffServ class, such as EF, BE, CSxx or AFxx (see `iptables -j DSCP --help` for more information).

The `chain` will be used to find traffic to mark. It can be any of the `iptables` built in chains belonging to the `mangle` table. The chain names are: INPUT, FORWARD, OUTPUT, PREROUTING and POSTROUTING. The 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 rule-params for more details.

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

## Examples

    # set DSCP field to 32, packets sent by the local machine
    dscp 32 OUTPUT

    # set DSCP field to 32 (hex 20), packets routed by the local machine
    dscp 0x20 FORWARD

    # set DSCP to DiffServ class EF, packets routed by the local machine
    #              and destined for port TCP/25 of 198.51.100.1
    dscp class EF FORWARD proto tcp dport 25 dst 198.51.100.1

## See Also

- sanewall
- sanewall.conf
- administration tool for IPv4 firewalls: iptables(8)
- show / manipulate routing, devices, policy routing and tunnels: ip(8)
- Linux Advanced Routing & Traffic Control HOWTO
- rule-params