I want to troubleshoot logstash server issue and need to generate syslog message from time to time. Is there a simple way that allows me to connect to a syslog server using TCP and send some arbitrary syslog messages?



Send each line of file.log towards syslog server on port 514

nc -q0 514 < file.log

Send a simple string that will generate a single log entry:

echo "message" | nc -q0 514

-q0 makes nc exit after sending:

-q seconds after EOF on stdin, wait the specified number of seconds and then quit.


The tcpflood utility has quite a lot of useful options. Below is a small subset of tcpflood options:

-t  target address (default
-p  target port (default 13514)
-c  number of connections (default 1)
-m  number of messages to send (connection is random)
-M  the message to be sent. Disables all message format options, as only that exact same message is sent.
-I  read specified input file, do NOT generate own test data. The test completes when eof is reached.
-D  randomly drop and re-establish connections. Useful for stress-testing the TCP receiver.
-T  transport to use. Currently supported: "udp", "tcp" (default) Note: UDP supports a single target port, only
  • You may add Nping to generate that TCP packets.
    – Biswapriyo
    Jul 14 '17 at 3:10
  • Thank you! I didn't realize syslog protocol is so simple. Even telnet works!
    – some user
    Jul 14 '17 at 3:49
  • 3
    Not sure if this has to be edited, i have nmap-ncat package and its --send-only versus -q0 Sep 20 '19 at 12:26

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.