Disabling the Firewall

Scenario

Disable the firewall on the VM. The firewall prevents the remote login in SSH mode.

Procedure

• For Red Hat 7.0, Red Hat 7.2, Red Hat 7.3, Red Hat 7.4, Oracle Linux 7, EulerOS, CentOS 7, CentOS 8, or SUSE15, run the following commands:

  systemctl disable firewalld.service

  systemctl stop firewalld.service

  Run the systemctl status firewalld.service command to check the firewall status.

• For Red Hat 6.7, Red Hat 6.8, Red Hat 6.9, CentOS 6.8, CentOS 6.9, Oracle Linux 6.8, or Oracle Linux 6.9, run the following commands:

  chkconfig iptables off

  service iptables stop

  Run the service iptables status command to check the firewall status.

  [root@localhost ~]# service iptables status
  iptables: Firewall is not running.

• For SUSE 12, run the following commands:

  systemctl disable SuSEfirewall2.service

  systemctl stop SuSEfirewall2.service

  Run the service SuSEfirewall2 status command to check the firewall status.

• For SUSE 11, run the following command:

  rcSuSEfirewall2 stop

  Then, run the following command:

  1. yast
  2. Choose Security and Users > Firewall > Disable Firewall Automatic Starting.
  3. Check whether automatic firewall starting is disabled.
     • If yes, click Cancel and then Quit.
     • If no, click Next, Finish, and then Quit.
• For Ubuntu 18.04, Ubuntu 16.04, Ubuntu 14.04, or Debian, run the following command:

  ufw disable

  If ufw is unavailable, download it from the official website (for example, https://packages.ubuntu.com/) and install it.

  The .deb installation package is as follows (the version number is for reference only):

  ufw_0.35-0ubuntu2_all.deb

  Alternatively, after configuring apt sources in SUSE/Red Hat/CentOS/Oracle Linux/Ubuntu/Debian, run the apt-get install ufw command to install it and then run the ufw disable command to disable the firewall.