Firewall

systemctl stop firewalld.service

systemctl disable firewalld.service

systemctl disable iptables.service

systemctl stop iptables.service

systemctl stop ip6tables.service

systemctl status firewalld.service

systemctl start firewalld.service

systemctl enable firewalld.service

systemctl restart firewalld.service

# iptables -L

# firewall-cmd --state

Disable IPtables

flush all IPtables rules. You can do it with the following command:

#  yum -y install nano wget net-tools NetworkManager-tui

# nmtui

# vi /etc/hosts

127.0.0.1   localhost localhost.localdomain localhost4 localhost4.localdomain4

192.168.1.100   mail.worldcm.net     mail

::1         localhost localhost.localdomain localhost6 localhost6.localdomain6

Allow enable Firewall

firewall-cmd --permanent --add-port=80/tcp

firewall-cmd --permanent --add-port=106/tcp

setsebool -P httpd_can_network_connect on

firewall-cmd --add-port=10000/tcp --permanent

firewall-cmd --add-port=20000/tcp --permanent

firewall-cmd --add-port=8000/tcp --permanent

firewall-cmd --add-service={pop3s,imaps} --permanent

firewall-cmd --add-port=465/tcp --permanent

firewall-cmd --permanent --add-service=smtp

firewall-cmd --permanent --add-port=587/tcp

firewall-cmd --permanent --add-port=465/tcp

firewall-cmd --permanent --add-port=110/tcp

firewall-cmd --permanent --add-service=pop3s

firewall-cmd --permanent --add-port=143/tcp

firewall-cmd --permanent --add-service=imaps

firewall-cmd --zone=public --add-port=993/tcp --permanent

firewall-cmd --zone=public --add-port=995/tcp --permanent

firewall-cmd --permanent --zone=public --add-port=5900/tcp

firewall-cmd --permanent --zone=public --add-service vnc-server

firewall-cmd --permanent --zone=public --add-service=cockpit

firewall-cmd --permanent --zone=public --add-service=http

firewall-cmd --permanent --zone=public --add-service=https

firewall-cmd --permanent --zone=public --add-port=5800-5900/tcp

firewall-cmd --permanent --add-service=ssh

firewall-cmd --reload

setsebool -P httpd_can_network_connect on

systemctl restart firewalld.service

Commands for Firewall

    ufw enable – turn on the firewall

    ufw disable – turn off the firewall

    ufw default allow – allow all connections by default

    ufw default deny – drop all connections by default

    ufw status – current rules and

    ufw allow port – to allow traffic on port

    ufw deny port – port block

    ufw deny from ip – ip block

Start/Stop and Enable/Disable FirewallD Service

 CentOS/RHEL 7 or Fedora 18+ versions, you should follow below instructions to manage FirewallD service.

Start FirewallD Service

# systemctl start firewalld

Stop FirewallD Service

# systemctl stop firewalld

Check the Status of FirewallD

# systemctl status firewalld

Check the State of FirewallD

# firewall-cmd --state

As an alternative, you can disable the firewalld service so that it doesn’t apply rules to packets and enable ones needed again.

Disable FirewallD Service

# systemctl disable firewalld

Enable FirewallD Service

# systemctl enable firewalld

Mask FirewallD Service

# systemctl mask firewalld

Also, you can mask the firewall service which creates a symbolic link of the firewall.service to  /dev/null, thus disabling the service.

Unmask FirewallD Service

# systemctl unmask firewalld

This is reverse of masking the service. This removes the symlink of the service created during masking, thus re-enabling the service.

How to Start/Stop and Enable/Disable IPtables Service

On RHEL/CentOS 6/5/4 and Fedora 12-18 iptables firewall comes as pre and later, the iptables service can be installed via:

# yum install iptables-services

Then, the service can be started, stopped or restarted via following commands:

Start Iptables Service

# systemctl start iptables

OR

# service iptables start

Stop Iptables Service

# systemctl stop iptables

OR

# service iptables stop

Disable Iptables Service

# systemctl disable iptables

Or

# service iptables save

# service iptables stop

Enable Iptables Service

# systemctl enable iptables

Or

# service iptables start

Check Status of Iptables Service

# systemctl status iptables

OR

# service iptables status

USER ADD

  useradd -m accesstel -s /sbin/nologin

    passwd accesstel

HTP port

firewall-cmd --permanent --add-port=80/tcp

setsebool -P httpd_can_network_connect on

webmin

firewall-cmd --add-port=10000/tcp --permanent

firewall-cmd --add-port=20000/tcp --permanent

SSl

[root@dlp ~]# firewall-cmd --add-service={pop3s,imaps} --permanent

success

[root@dlp ~]# firewall-cmd --add-port=465/tcp --permanent

success

[root@dlp ~]# firewall-cmd --reload

Step 10 » Add the firewall rules to allow 25, 587 and 465 ports.

[root@mail ~]# firewall-cmd --permanent --add-service=smtp

[root@mail ~]# firewall-cmd --permanent --add-port=587/tcp

[root@mail ~]# firewall-cmd --permanent --add-port=465/tcp

[root@mail ~]# firewall-cmd --reload

Now start testing connectivity for each ports 25,587 and 465 using telnet and make

Step 14 » Add firewall rules to allow 110,143,993 and 995.

[root@mail ~]# firewall-cmd --permanent --add-port=110/tcp

[root@mail ~]# firewall-cmd --permanent --add-service=pop3s

[root@mail ~]# firewall-cmd --permanent --add-port=143/tcp

[root@mail ~]# firewall-cmd --permanent --add-service=imaps

[root@mail ~]# firewall-cmd --reload

Check the connectivity for the ports 110,143,993 and 995 using telnet.

o unblock all these ports from firewall, run the following commands.

   firewall-cmd --permanent --add-service=smtp     firewall-cmd --permanent --add-port=587/tcp     firewall-cmd --permanent --add-port=465/tcp     firewall-cmd --permanent --add-port=110/tcp     firewall-cmd --permanent --add-service=pop3s     firewall-cmd --permanent --add-port=143/tcp     firewall-cmd --permanent --add-service=imaps     firewall-cmd --permanent --add-service=http     firewall-cmd --reload

 telnet mail.yourdomain.com smtp

If you do not have telnet installed, then you can run the following command to install telnet.

   yum -y install telnet

Zimbra Port

[root@mail ~]# firewall-cmd --permanent --add-port={25,80,110,143,443,465,587,993,995,5222,5223,9071,7071}/tcp success [root@mail ~]# firewall-cmd --reload

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