CentOS iptables is accessible only on ports 22 and 80.

CentOS iptables is accessible only on ports 22 and 80.

Iptables is accessible only on ports 22 and 80.

Run the netstat-tnl command to check which ports are opened on the current server.

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Netstat-tnl

View firewall settings

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Iptables-L-n

Open ports 22 and 80

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Iptables-a input-p tcp -- dport 22-j ACCEPT

Iptables-a output-p tcp -- sport 22-j ACCEPT

Iptables-a input-p tcp -- dport 80-m state -- state NEW, ESTABLISHED-j ACCEPT

Iptables-a output-p tcp -- sport 80-m state -- state NEW, ESTABLISHED-j ACCEPT

Cancel access rules for other ports

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Iptables-P INPUT DROP

Iptables-P FORWARD DROP

Iptables-P OUTPUT DROP

Allow local loopback interface (that is, allow local access to the local machine)

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Iptables-a input-s 127.0.0.1-d 127.0.0.1-j ACCEPT

Allow established or related connections (such as database links)

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Iptables-a input-m state -- state ESTABLISHED, RELATED-j ACCEPT

Allow external access from all hosts

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Iptables-a output-j ACCEPT

Save Configuration:

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Service iptables save