3.3.3. Configuring the iptables Firewall to Allow Cluster Components

Listed below are example iptable rules for enabling IP ports needed by Red Hat Enterprise Linux 6 (with High Availability Add-on). Please note that these examples use 192.168.1.0/24 as a subnet, but you will need to replace 192.168.1.0/24 with the appropriate subnet if you use these rules.
For cman (Cluster Manager), use the following filtering.
$ iptables -I INPUT -m state --state NEW -m multiport -p udp -s 192.168.1.0/24 -d 192.168.1.0/24 --dports 5404,5405 -j ACCEPT
$ iptables -I INPUT -m addrtype --dst-type MULTICAST -m state --state NEW -m multiport -p udp -s 192.168.1.0/24 --dports 5404,5405 -j ACCEPT
For dlm (Distributed Lock Manager):
$ iptables -I INPUT -m state --state NEW -p tcp -s 192.168.1.0/24 -d 192.168.1.0/24 --dport 21064 -j ACCEPT 
For ricci (part of Conga remote agent):
$ iptables -I INPUT -m state --state NEW -p tcp -s 192.168.1.0/24 -d 192.168.1.0/24 --dport 11111 -j ACCEPT
For modclusterd (part of Conga remote agent):
$ iptables -I INPUT -m state --state NEW -p tcp -s 192.168.1.0/24 -d 192.168.1.0/24 --dport 16851 -j ACCEPT
For luci (Conga User Interface server):
$ iptables -I INPUT -m state --state NEW -p tcp -s 192.168.1.0/24 -d 192.168.1.0/24 --dport 8084 -j ACCEPT
For igmp (Internet Group Management Protocol):
$ iptables -I INPUT -p igmp -j ACCEPT
After executing these commands, enter the following command to save the current configuration for the changes to be persistent during reboot.
$ service iptables save ; service iptables restart