Here are few simple steps on how to update SSH Port in CentOS 7 VPS or Dedicated Server
Edit the SSHD configuration file :
nano -w /etc/ssh/sshd_config
(if nano is not installed use any other text editor or install it with yum -y install nano)
and change the Port number from 22 to any custom port you choose :
e.g. Port 18989
Make sure to even remove the # mark before Port
Save the config file
SELinux is enabled by default in CentOS 7 so you need to even inform SELinux to change the SSH Port else it won’t allow you to restart SSHD with new Port.
To run semanage for updating SSHD Port you nee to first install policycoreutils, install it with :
yum -y install policycoreutils-python
now update SeLinux policy to allow new port for SSH service. to do this, run below :
semanage port -a -t ssh_port_t -p tcp 18989
now you need to update Firewall policy to allow new SSH Port, to do this run below :
firewall-cmd –permanent –zone=public –add-port=18989/tcp
firewall-cmd –reload
systemctl restart sshd.service
SSHD Port is now updated, you can now connect to your new SSH Port: 18989