3.5.3.2. Rules for Passive Connections
The rules for passive connections assign the appropriate firewall mark to connections coming in from the Internet to the floating IP for the service on a wide range of ports — 10,000 to 20,000.
Warning
If you are limiting the port range for passive connections, you must also configure the VSFTP server to use a matching port range. This can be accomplished by adding the following lines to
/etc/vsftpd.conf:
pasv_min_port=10000
pasv_max_port=20000
You must also control the address that the server displays to the client for passive FTP connections. In a NAT routed LVS system, add the following line to
/etc/vsftpd.conf to override the real server IP address to the VIP, which is what the client sees upon connection. For example:
pasv_address=n.n.n.n
Replace n.n.n.n with the VIP address of the LVS system.
For configuration of other FTP servers, consult the respective documentation.
This range should be a wide enough for most situations; however, you can increase this number to include all available non-secured ports by changing
10000:20000 in the commands below to 1024:65535.
The following
iptables commands have the net effect of assigning any traffic addressed to the floating IP on the appropriate ports a firewall mark of 21, which is in turn recognized by IPVS and forwarded appropriately:
/sbin/iptables -t mangle -A PREROUTING -p tcp -d n.n.n.n/32 --dport 21 -j MARK --set-mark 21
/sbin/iptables -t mangle -A PREROUTING -p tcp -d n.n.n.n/32 --dport 10000:20000 -j MARK --set-mark 21
In the
iptables commands, n.n.n.n should be replaced with the floating IP for the FTP virtual server defined in the VIRTUAL SERVER subsection of Piranha Configuration Tool.
Warning
The commands above take effect immediately, but do not persist through a reboot of the system. To ensure network packet filter settings are restored after a reboot, see Section 3.6, “Saving Network Packet Filter Settings”
Finally, you need to be sure that the appropriate service is set to activate on the proper runlevels. For more on this, refer to Section 2.1, “Configuring Services on the LVS Routers”.
