How to Configure selinux with iptables in Centos/Red Hat.

Security-Enhanced Linux (SELinux) is a Linux kernel security module that supports access control security policies, mandatory access controls (MAC).

SELinux is a set of kernel modifications and user-space tools that have been added to various Linux distributions.

Install iptables service

yum install policycoreutils iptables-services -y

Start & Enable Iptables service.

systemctl start iptables
systemctl enable iptables

Disable Firewall service.

systemctl disable firewalld

Stop Firewall service.

systemctl stop firewalld

Check Firewall service status.

systemctl status firewalld

Here is the command output.

Fig 1

Check SELinux status.

sestatus

Here is the command output.

Fig. 3

To disable SELinux status.Run the following Command.

setenforce 0

To disable permanently SELinux status.Open /etc/sysconfig/selinux file.

vim /etc/sysconfig/selinux

Set SELinux=Disabled.

Here is the command output.

Fig. 4

Restart Iptables Service.

systemctl restart iptables

Iptables Syntx.

iptables --table TABLE -A/-C/-D... CHAIN rule --jump Target

 Removes/Drops all the traffic coming on any port.

iptables -t filter --append INPUT -j DROP

Delete rule from the specified chain.

iptables -t filter --delete INPUT 2

checks the specified rule is present in the INPUT chain.

iptables -t filter --check INPUT -s ip-address -j DROP ; echo $?

Appends a rule in input chain to drop all udp packets.

iptables -t filter -A INPUT -p udp -j DROP

Appends a rule in input chain to accept all packets originating from Ip-address.

iptables -t filter -A INPUT -s ip-address -j ACCEPT

Appends a rule in output chain to drop all packets destined for IP-address.

iptables -t filter -A OUTPUT -d Ip-address -j DROP

Appends a rule in input chain to drop all packets destined for wireless interface.

iptables -t filter -A INPUT -i wlan0 -j DROP

Adds a rule in the FORWARD chain to drop all packets. 

iptables -t filter -A FORWARD -j DROP

Remove all filtering rules and user created chains.

iptables --flush

Save the iptables.

iptables-save

Here is the command output.

Fig. 6

Restoring iptables.

iptables-restore

List the Iptables.

iptables -L

Here is the command output.

Fig. 7

 

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