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CentOS 7 how to change the default port of ssh, many novices are not very clear about this, in order to help you solve this problem, the following editor will explain in detail for you, people with this need can come to learn, I hope you can gain something.

$vi / etc/ssh/sshd_config

Uncomment # Port 22 and add the new port Port 1111 you need to modify on the next line. (Port 22 is not deleted here to prevent the modified new port from becoming inaccessible, making it impossible to connect to the server using ssh.

Port 22Port 1111

Restart the sshd service after modifying and saving the sshd_config file:

$systemctl restart sshd

After exiting the ssh session, connect with the new port:

Configure Firewall firewalld

Enable the firewall & & check the firewall status:

$systemctl enable firewalld

$systemctl start firewalld

$systemctl status firewalld

Firewalld.service-firewalld-dynamic firewall daemon

> Loaded: loaded (/ usr/lib/systemd/system/firewalld.service; enabled; vendor preset: enabled)

> Active: active (running) since II 2016-12-20 02:12:59 CST; 1 day 13h ago

> Main PID: 10379 (firewalld)

> CGroup: / system.slice/firewalld.service

> └─ 10379 / usr/bin/python-Es / usr/sbin/firewalld-- nofork-- nopid

$firewall-cmd-state

Running

# in case the new port does not work, expose port 22 first

$firewall-cmd-permanent-zone=public-add-port=22/tcp

$firewall-cmd-permanent-zone=public-add-port=1111/tcp

Success

Reload firewall

$firewall-cmd-reload

View exposed port rules

$firewall-cmd-permanent-list-port

443/tcp 80/tcp 22/tcp 1111/tcp

$firewall-cmd-zone=public-list-all

Public (default, active)

Interfaces: eth0 eth2

Sources:

Services: dhcpv6-client ssh

Ports: 443/tcp 80/tcp 22/tcp 1111/tcp

Masquerade: no

Forward-ports:

Icmp-blocks:

Rich rules:

After exiting ssh, try to connect to the new port

$ssh-p 1111 root@example.com

If you log in successfully, you can do the finishing touches.

Disable port 22

Delete ssh allowed port

$vi / etc/ssh/sshd_config

# Port 22

Port 1111

$systemctl restart sshd

# use ss command to check the port that ssh listens to. There is no 22 proof that the modification is successful.

$ss-tnlp | grep ssh

LISTEN 0 128 *: 1111:

Users: (("sshd", 18233)

Firewall removes port 22

$firewall-cmd-permanent-zone=public-remove-port=22/tcp

Success

$firewall-cmd-reload

$firewall-cmd-permanent-list-port

443/tcp 80/tcp 1111/tcp

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