一、修改ssh默認端口，防止暴力破解，讓系統安全多一點點：
i. 在配置文件/etc/ssh/sshd_config文件中修改
17 Port 5522 18 #AddressFamily any 19 #ListenAddress 0.0.0.0 20 #ListenAddress ::
ii. 然后重啟sshd
[root@localhost ~]# systemctl restart sshd
iii. 如果自定義端口，重啟sshd出現如下報錯：
[root@localhost ~]# systemctl restart sshd Job for sshd.service failed because the control process exited with error code. See "systemctl status sshd.service" and "journalctl -xe" for details.
查看詳細如下：
[root@localhost ~]# journalctl -xe -- -- Unit sshd.service has failed. -- -- The result is failed. Jul 19 22:39:08 localhost.localdomain systemd[1]: Unit sshd.service entered failed state. Jul 19 22:39:08 localhost.localdomain systemd[1]: sshd.service failed. Jul 19 22:39:08 localhost.localdomain polkitd[695]: Unregistered Authentication Agent for unix-process:3128:1153611 Jul 19 22:39:38 localhost.localdomain polkitd[695]: Registered Authentication Agent for unix-process:3140:1156691 (s Jul 19 22:39:38 localhost.localdomain systemd[1]: Starting OpenSSH server daemon... -- Subject: Unit sshd.service has begun start-up -- Defined-By: systemd -- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel -- -- Unit sshd.service has begun starting up. Jul 19 22:39:38 localhost.localdomain sshd[3146]: error: Bind to port 5522 on 0.0.0.0 failed: Permission denied. Jul 19 22:39:38 localhost.localdomain sshd[3146]: error: Bind to port 5522 on :: failed: Permission denied. Jul 19 22:39:38 localhost.localdomain sshd[3146]: fatal: Cannot bind any address. Jul 19 22:39:38 localhost.localdomain systemd[1]: sshd.service: main process exited, code=exited, status=255/n/a Jul 19 22:39:38 localhost.localdomain systemd[1]: Failed to start OpenSSH server daemon. -- Subject: Unit sshd.service has failed -- Defined-By: systemd -- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel -- -- Unit sshd.service has failed. -- -- The result is failed. Jul 19 22:39:38 localhost.localdomain systemd[1]: Unit sshd.service entered failed state. Jul 19 22:39:38 localhost.localdomain systemd[1]: sshd.service failed. Jul 19 22:39:38 localhost.localdomain polkitd[695]: Unregistered Authentication Agent for unix-process:3140:1156691
iv. 解決辦法，關閉SELinux即可
# 臨時關閉 [root@localhost ~]# setenforce 0 # 永久關閉 [root@localhost ~]# vim /etc/selinux/config --------------------修改配置------------------------ SELINUX=disabled
v. 檢查是否成功
注：如果重啟sshd成功沒有出現報錯，但是檢查端口時無效，也是跟SELinux有關，請把它Disable。
[root@localhost ~]# netstat -ntlp | grep sshd tcp 0 0 0.0.0.0:5522 0.0.0.0:* LISTEN 3166/sshd tcp6 0 0 :::5522 :::* LISTEN 3166/sshd
二、配置sshd監聽多端口
注：必須把上面的port 5522注釋掉，然后增加listenAddress
[root@localhost ~]# vim /etc/ssh/sshd_config ---------------- 配置如下 ---------------- #Port 5522 #AddressFamily any #ListenAddress 0.0.0.0 #ListenAddress :: ListenAddress 0.0.0.0:22 ListenAddress 0.0.0.0:5522
重啟sshd：
[root@localhost ~]# systemctl restart sshd
檢查是否成功：
注：如果配置無效，請檢查SELinux是否Disable
[root@localhost ~]# netstat -ntlp | grep sshd tcp 0 0 0.0.0.0:5522 0.0.0.0:* LISTEN 3323/sshd tcp 0 0 0.0.0.0:22 0.0.0.0:* LISTEN 3323/sshd
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