In Linux, the iptables firewall releases the port to reject the port and view the opened port.
I use fedora 14.
1. view the port enabled by iptables firewall:/etc/init. d/iptables status
[Root @ hzswtb2-mpc ~] #/Etc/rc. d/init. d/iptables status or service iptables status
Table: filter
Chain INPUT (policy ACCEPT)
Num target prot opt source destination
1 ACCEPT tcp -- 0.0.0.0/0 0.0.0.0/0 tcp dpt: 3306
Chain FORWARD (policy ACCEPT)
Num target prot opt source destination
Chain OUTPUT (policy ACCEPT)
Num target prot opt source destination
2. Enable tcp port 8080
/Sbin/iptables-I INPUT-p tcp -- dport 8080-j ACCEPT
/Etc/rc. d/init. d/iptables save or service iptables save # save the configuration/etc/rc. d/init. d/iptables restart or service iptables restart # restart the service
[Root @ hzswtb2-mpc ~] #/Sbin/iptables-I INPUT-p tcp -- dport 8080-j ACCEPT
[Root @ hzswtb2-mpc ~] #/Etc/rc. d/init. d/iptables save
Iptables: Saving firewall rules to/etc/sysconfig/iptables: [OK]
[Root @ hzswtb2-mpc ~] #/Etc/rc. d/init. d/iptables restart
Iptables: Flushing firewall rules: [OK]
Iptables: Setting chains to policy ACCEPT: filter [OK]
Iptables: Unloading modules: [OK]
Iptables: Applying firewall rules: [OK]
[Root @ hzswtb2-mpc ~] # Service iptables status
Table: filter
Chain INPUT (policy ACCEPT)
Num target prot opt source destination
1 ACCEPT tcp -- 0.0.0.0/0 0.0.0.0/0 tcp dpt: 8080
2 ACCEPT tcp -- 0.0.0.0/0 0.0.0.0/0 tcp dpt: 3306
3. Delete chain INPUT and specify Rule 1;
[Root @ hzswtb2-mpc ~] # Iptables-d input 1
[Root @ hzswtb2-mpc ~] # Service iptables status
Table: filter
Chain INPUT (policy ACCEPT)
Num target prot opt source destination
1 ACCEPT tcp -- 0.0.0.0/0 0.0.0.0/0 tcp dpt: 3306
Chain FORWARD (policy ACCEPT)
Num target prot opt source destination
Chain OUTPUT (policy ACCEPT)
Num target prot opt source destination
4. Reject specifies the port;
[Root @ hzswtb2-mpc ~] #/Sbin/iptables-I INPUT-p tcp -- dport 8080-j REJECT
[Root @ hzswtb2-mpc ~] # Service iptables status
Table: filter
Chain INPUT (policy ACCEPT)
Num target prot opt source destination
1 REJECT tcp -- 0.0.0.0/0 0.0.0.0/0 tcp dpt: 8080 reject-with icmp-port-unreachable
2 ACCEPT tcp -- 0.0.0.0/0 0.0.0.0/0 tcp dpt: 3306
Chain FORWARD (policy ACCEPT)
Num target prot opt source destination
Chain OUTPUT (policy ACCEPT)
Num target prot opt source destination