NAME

       firehol-dscp - set the DSCP field in the packet header

SYNOPSIS

       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.

              Note

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

       Set value to a decimal or hexadecimal (0xnn) number to set an explicit DSCP value or use class classid to
       use an iptables(8) 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(8) 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 firehol-params(5) 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

       • firehol(1) - FireHOL program

       • firehol.conf(5) - FireHOL configuration

       • firehol-params(5) - optional rule parameters

       • iptables(8) - administration tool for IPv4 firewalls

       • ip6tables(8) - administration tool for IPv6 firewalls

       • ip(8) - show / manipulate routing, devices, policy routing and tunnels

       • FireHOL Website

       • FireHOL Online PDF Manual

       • FireHOL Online Documentation

       • Linux Advanced Routing & Traffic Control HOWTO

AUTHORS

       FireHOL Team.

FireHOL Reference                               Built 13 Apr 2025                                firehol-dscp(5)