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.