I installed "knock-server" and configure it as below:
Code: Select all
[options]
UseSyslog
logfile = /var/log/knockd.log
OPTIONS="-i enp0s3"
[openSSH]
sequence = 32512,8425,27705
seq_timeout = 5
command = firewall-cmd --add-port=22/tcp
tcpflags = syn
[closeSSH]
sequence = 9136,17752,45700
seq_timeout = 5
command = firewall-cmd --remove-port=22/tcp
tcpflags = syn
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# service knockd start
Starting knockd (via systemctl): Job for knockd.service failed because the control process exited with error code. See "systemctl status knockd.service" and "journalctl -xe" for details.
[FAILED]
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# systemctl status knockd.service
● knockd.service - SYSV: Knock is a port-knocking server/client.
Loaded: loaded (/etc/rc.d/init.d/knockd)
Active: failed (Result: exit-code) since Wed 2019-01-23 06:42:31 EST; 30s ago
Docs: man:systemd-sysv-generator(8)
Process: 18408 ExecStart=/etc/rc.d/init.d/knockd start (code=exited, status=1/FAILURE)
Jan 23 06:42:31 localhost.localdomain knockd[18408]: -p, --pidfile use an alternate pidfile
Jan 23 06:42:31 localhost.localdomain knockd[18408]: -g, --logfile use an alternate logfile
Jan 23 06:42:31 localhost.localdomain knockd[18408]: -v, --verbose be verbose
Jan 23 06:42:31 localhost.localdomain knockd[18408]: -V, --version display version
Jan 23 06:42:31 localhost.localdomain knockd[18408]: -h, --help this help
Jan 23 06:42:31 localhost.localdomain knockd[18408]: [FAILED]
Jan 23 06:42:31 localhost.localdomain systemd[1]: knockd.service: control process exited, code=exited status=1
Jan 23 06:42:31 localhost.localdomain systemd[1]: Failed to start SYSV: Knock is a port-knocking server/client..
Jan 23 06:42:31 localhost.localdomain systemd[1]: Unit knockd.service entered failed state.
Jan 23 06:42:31 localhost.localdomain systemd[1]: knockd.service failed.
Thank you.