IPtables: open port for specific IP

The following are examples of allow a host or a range of hosts visit port 8080

sudo vim /etc/sysconfig/iptables

# the following rule specifies only Ip 101.2.3.44 can visit port 8080

-A RH-Firewall-1-INPUT -m state --state NEW -m tcp -p tcp -s 101.2.3.44 --dport 8080 -j ACCEPT

# a range of IPs are allowed to visit port 8080

-A RH-Firewall-1-INPUT -m state --state NEW -m tcp -p tcp -src-range 101.2.3.44-1.2.3.54 --dport 8080 -j ACCEPT

# restart iptables service to make the change take effect

sudo /etc/init.d/iptables restart