Firewall mark classifier in tc((82)1tFi2r0e1w5a)ll mark classifier in tc(8)

          fw - fwmark traffic control filter

          tc filter ... fw [ CLASSID ] [  action ACTION_SPEC ]

          the fw filter allows to classify packets based on a previ-
          ously set fwmark by iptables.  If it is identical to the
          filter's handle, the filter matches.  iptables allows to
          mark single packets with the MARK target, or whole connec-
          tions using CONNMARK.  The benefit of using this filter
          instead of doing the heavy-lifting with tc itself is that on
          one hand it might be convenient to keep packet filtering and
          classification in one place, possibly having to match a
          packet just once, and on the other users familiar with
          iptables but not tc will have a less hard time adding QoS to
          their setups.

          classid CLASSID
               Push matching packets to the class identified by

          action ACTION_SPEC
               Apply an action from the generic actions framework on
               matching packets.

          Take e.g. the following tc filter statement:

               tc filter add ... handle 6 fw classid 1:1

          will match if the packet's fwmark value is 6.  This is a
          sample iptables statement marking packets coming in on eth0:

               iptables -t mangle -A PREROUTING -i eth0 -j MARK --set-mark 6

          tc(8), iptables(8), iptables-extensions(8)

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