man 8 gact

Generic actions in tc(8)             Linux            Generic actions in tc(8)

NAME
       gact - generic action

SYNOPSIS
       tc ... action gact CONTROL [ RAND ] [ INDEX ]
       CONTROL := { reclassify | drop | continue | pass | pipe |
               goto chain CHAIN_INDEX |
               jump JUMP_COUNT }

       RAND := random RANDTYPE CONTROL VAL
       RANDTYPE := { netrand | determ }
       VAL := number not exceeding 10000
       JUMP_COUNT := absolute jump from start of action list
       INDEX := index value used

DESCRIPTION
       The  gact  action  allows  reclassify,  dropping, passing, or accepting
       packets.  At the moment there are only two algorithms. One is determin-
       istic and the other uses internal kernel netrand.

OPTIONS
       random RANDTYPE CONTROL VAL
              The probability of taking the action expressed in terms of 1 out
              of VAL packets.

       CONTROL
              Indicate how tc should proceed if the packet matches.  For a de-
              scription of the possible CONTROL values, see tc-actions(8).

EXAMPLES
       Apply a rule on ingress to drop packets from a given source address.
              # tc filter add dev eth0 parent ffff: protocol ip prio 6 u32 match ip src 10.0.0.9/32 flowid 1:16 action drop

       Allow 1 out 10 packets from source randomly using the netrand generator
              # tc filter add dev eth0 parent ffff: protocol ip prio 6 u32 match ip src 10.0.0.9/32 flowid 1:16 action drop random netrand ok 10

       Deterministically accept every second packet
              # tc filter add dev eth0 parent ffff: protocol ip prio 6 u32 match ip src 10.0.0.9/32 flowid 1:16 action drop random determ ok 2

SEE ALSO
       tc(8), tc-actions(8), tc-u32(8)

iproute2                          11 Jan 2023         Generic actions in tc(8)