Assign Firewall Package marks in IPTables

To assign firewall marks to a packet destined for a particular port, the administrator must use iptables.

This solution illustrates how to bundle HTTP and HTTPS as an example, however FTP is another commonly clustered multi-port protocol. If an LVS cluster is used for FTP services.

The basic rule to remember when using firewall marks is that for every protocol using a firewall mark in Piranha Configuration Tool there must be a commensurate iptables rule to assign marks to the network packets.

Before creating network packet filter rules, make sure there are no rules already in place. To do this, open a shell prompt, login as root, and type:

/sbin/service iptables status

If iptables is not running, the prompt will instantly reappear.

If iptables is active, it displays a set of rules. If rules are present, type the following command:

/sbin/service iptables stop

If the rules already in place are important, check the contents of /etc/sysconfig/iptables and copy any rules worth keeping to a safe place before proceeding.

Below are rules which assign the same firewall mark, 80, to incoming traffic destined for the floating IP address, n.n.n.n, on ports 80 and 443. Also note that you must log in as root and load the module for iptables before issuing rules for the first time.

/sbin/modprobe ip_tables
/sbin/iptables -t mangle -A PREROUTING -p tcp -d n.n.n.n/32 --dport 80 -j MARK --set-mark 80
/sbin/iptables -t mangle-A PREROUTING -p tcp -d n.n.n.n/32 --dport 443 -j MARK --set-mark 80

In the above iptables commands, n.n.n.n should be replaced with the floating IP for your HTTP and HTTPS virtual servers. These commands have the net effect of assigning any traffic addressed to the VIP on the appropriate ports a firewall mark of 80, which in turn is recognized by IPVS and forwarded appropriately.

Warning: The commands above will take effect immediately, but do not persist through a reboot of the system. hint:

chkconfig iptables on
service iptables save
service iptables restart

...test it agian...