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--- linux_security_firewalld [2019/11/14 10:43] – created andonovj
+++ linux_security_firewalld [2019/11/14 21:34] (current) – external edit 127.0.0.1
@@ Line 10: / Line 10: @@
 That is done mainly with the firewall by allowing / blocking ports. Let's see how it is done.
-======Firewalld Management======
+======Firewall Management======
-Firewalld is the newer version of the iptables and allows port forwarding and
+The firewall management depend on the operation linux type:
+  * RedHat based
+  * Debian Based
+=====Redhat base=====
+In Redhat based Linux, the firewall is controlled by either:
+  * Iptables (older)
+  * Firewalld (newer)
+Firewalld is the newer version of the iptables and allows port forwarding and connection management. In other words we can limit certain requests on certain ports.
+Let's see how to manage it:
+====Install Firewalld====
+By default firewalld is installed although if you using minimal installation it might not be. So to install it use the following command:
+<sxh bash>
+systemctl enable firewalld
+systemctl start firewalld
+</sxh>
+====Allow Port====
+So let's allow SSH to our server:
+<sxh bash>
+firewall-cmd --permanent --add-port=22/tcp
+</sxh>
+====Port Fowarding====
+Let's see you web server running on port 8000, but you want be able to access it with port 80 or 443.
+In that case we can use port forwarding in order for incomming requests for ports: 80/443 to be redirected to port 8000:
+<sxh bash>
+firewall-cmd --permanent --add-forward-port=port=80:proto=tcp:toport=8000
+firewall-cmd --permanent --add-forward-port=port=443:proto=tcp:toport=8000
+</sxh>
+That's it, now we have to just reload the configuration:
+<sxh bash>
+firewall-cmd --reload
+</sxh>
+That's it, now our rules can be seen below:
+<sxh bash>
+[root@ip-172-31-7-118 ~]# firewall-cmd --list-all
+public (active)
+  target: default
+  icmp-block-inversion: no
+  interfaces: eth0
+  sources:
+  services: cockpit dhcpv6-client ssh
+  ports:
+  protocols:
+  masquerade: no
+  forward-ports: port=443:proto=tcp:toport=8000:toaddr=
+        port=80:proto=tcp:toport=8000:toaddr=
+  source-ports:
+  icmp-blocks:
+  rich rules:
+[root@ip-172-31-7-118 ~]#
+</sxh>
+====Delete a rule====
+In order to delete a rule, we can use the same command as for addition, just intead of add we use "remove" :)
+<sxh bash>
+firewall-cmd --permanent --remove-forward-port=port=80:proto=tcp:toport=8000
+firewall-cmd --permanent --remove-forward-port=port=443:proto=tcp:toport=8000
+</sxh>
+To delete ALL rules from firewalld, we can also remove the zones:
+<sxh bash>
+rm -rf  /etc/firewalld/zones/
+</sxh>
+That will delete all rules and the firewalld will re-create the public zone once it is restarted.
+=====Debian based=====
+In debian based, the configuration is a little bit different:
+====Install/Enable====
+To install the firewall management tool in Debian based use the following command:
+<sxh bash>
+apt-get install -y ufw
+update-rc.d ufw enable
+service ufw start
+</sxh>
+====Allow port====
+<sxh bash>
+ufw allow 22
+ufw allow 443
+ufw allow 5901
+</sxh>
+====Port Forwarding====
+To allow port forwarding in debian based, we have to edit the file: /etc/ufw/before.rules
+<sxh bash>
+*nat
+:PREROUTING ACCEPT [0:0]
+-A PREROUTING -p tcp --dport 80 -j REDIRECT --to-port 8000
+-A PREROUTING -p tcp --dport 443 -j REDIRECT --to-port 8000
+COMMIT
+</sxh>
+And then reload/enable the configuration again :)
+<sxh bash>
+ufw enable
+</sxh>
+You might need to reboot the entire server, but before that try to remove the service itself :).
+Cheers.