# man > tc-simple(8)

Simple action in [tc(8)](https://www.chedong.com/phpMan.php/man/tc/8/markdown)                          Linux                         Simple action in [tc(8)](https://www.chedong.com/phpMan.php/man/tc/8/markdown)



## NAME
       simple - basic example action

## SYNOPSIS
       **tc** ... **action** **simple** [ **sdata** _STRING_ ] [ **index** _INDEX_ ] [ _CONTROL_ ]

       _CONTROL_ := { **reclassify** | **pipe** | **drop** | **continue** | **ok** }


## DESCRIPTION
       This  is  a  pedagogical example rather than an actually useful action. Upon every access, it
       prints the given _STRING_ which may be of arbitrary length.

## OPTIONS
       **sdata** _STRING_
              The actual string to print.

       **index** _INDEX_
              Optional action index value.

       _CONTROL_
              Indicate how **tc** should proceed after executing the action. For a  description  of  the
              possible _CONTROL_ values, see [**tc-actions**(8)](https://www.chedong.com/phpMan.php/man/tc-actions/8/markdown).

## EXAMPLES
       The  following  example makes the kernel yell "Incoming ICMP!" every time it sees an incoming
       ICMP on eth0. Steps are:

       1)  Add an ingress qdisc point to eth0

       2)  Start a chain on ingress of eth0 that first matches ICMP then invokes the  simple  action
           to shout.

       3)  display stats and show that no packet has been seen by the action

       4)  Send one ping packet to google (expect to receive a response back)

       5)  grep the logs to see the logged message

       6)  display stats again and observe increment by 1

             hadi@noma1:$ tc qdisc add dev eth0 ingress
             hadi@noma1:$tc filter add dev eth0 parent ffff: protocol ip prio 5 \
                 u32 match ip protocol 1 0xff flowid 1:1 action simple sdata "Incoming ICMP"

             hadi@noma1:$ sudo tc -s filter ls  dev eth0 parent ffff:
              filter protocol ip pref 5 u32
              filter protocol ip pref 5 u32 fh 800: ht divisor 1
              filter protocol ip pref 5 u32 fh [800::800](https://www.chedong.com/phpMan.php/perldoc/800%3A%3A800/markdown) order 2048 key ht 800 bkt 0 flowid 1:1
                match 00010000/00ff0000 at 8
                action order 1: Simple <Incoming ICMP>
                 index 4 ref 1 bind 1 installed 29 sec used 29 sec
                 Action statistics:
                     Sent 0 bytes 0 pkt (dropped 0, overlimits 0 requeues 0)
                     backlog 0b 0p requeues 0


             hadi@noma1$ ping -c 1 www.google.ca
             PING www.google.ca (74.125.225.120) [56(84)](https://www.chedong.com/phpMan.php/man/56/84/markdown) bytes of data.
             64 bytes from ord08s08-in-f24.1e100.net (74.125.225.120): icmp_req=1 ttl=53 time=31.3 ms

             --- www.google.ca ping statistics ---
             1 packets transmitted, 1 received, 0% packet loss, time 0ms
             rtt min/avg/max/mdev = 31.316/31.316/31.316/0.000 ms

             hadi@noma1$ dmesg | grep simple
             [135354.473951] simple: Incoming ICMP_1

             hadi@noma1$ sudo tc/tc -s filter ls  dev eth0 parent ffff:
             filter protocol ip pref 5 u32
             filter protocol ip pref 5 u32 fh 800: ht divisor 1
             filter protocol ip pref 5 u32 fh [800::800](https://www.chedong.com/phpMan.php/perldoc/800%3A%3A800/markdown) order 2048 key ht 800 bkt 0 flowid 1:1
               match 00010000/00ff0000 at 8
                action order 1: Simple <Incoming ICMP>
                 index 4 ref 1 bind 1 installed 206 sec used 67 sec
                Action statistics:
                Sent 84 bytes 1 pkt (dropped 0, overlimits 0 requeues 0)
                backlog 0b 0p requeues 0

## SEE ALSO
       [**tc**(8)](https://www.chedong.com/phpMan.php/man/tc/8/markdown) [**tc-actions**(8)](https://www.chedong.com/phpMan.php/man/tc-actions/8/markdown)



iproute2                                     12 Jan 2015                      Simple action in [tc(8)](https://www.chedong.com/phpMan.php/man/tc/8/markdown)