Load balancing FTP

This application note is intended to help you to configure the Aloha to load-balance File Transfer Protocol (FTP)


Objective

Ensure high availability of a FTP service.


Constraints

You must have at least a couple of server with FTP server in active mode.


Complexity

2


Versions

v4.1 and later

ALOHA load balancer Load balancing FTP


Target network diagram

Standard architecture, as bellow:


Context

The clients will use the FTP service on the IP 192.168.0.100.

The Aloha load balance traffic to the two FTP servers 192.168.1.10 and 192.168.1.11.

The Aloha is configured in NAT mode using LVS/layer 4 load balancing service.

There is currently two ways to load-balance FTP with the Aloha.

  1. Basic configuration, easy to configure
  2. Advanced configuration, a bit harder than basic, but ensure a better load balancing

You should use basic configuration when you want to provide a high available FTP service.

Prefer second method if you want to improve load balancing, as well as providing high availability


Common configuration

In both cases, you’ll have to enable the flow manager and the LVS service at start up.

Flow manager service

If your flowmgr service is not configured to automatic startup when the Aloha boots up, then go in the Service tab of the GUI and click on the flowmgr setup icon .

If there is a line “no autostart”, then delete it.

Click on [OK] then [Close]

Then restart the flowmgr service by clicking on the restart icon .

LVS service

If your lvs service is not configured to automatic startup when the Aloha boots up, then go in the Service tab of the GUI and click on the lvs setup icon .

If there is a line “no autostart”, then delete it.

Click on [OK] then [Close]

Then restart the lvs service by clicking on the restart icon .


Basic configuration

Flow director configuration

On the GUI, click on Flows tab, then add the configuration below:

flow f_ftp director d_ftp
	match proto tcp dst 192.168.0.100 dstport 20:21
	match proto tcp dst 192.168.0.100 dstport 1024:65535

Click on [OK], then [Apply].

LB Layer 4 configuration

On the GUI, click on LB Layer 4 tab, then add the configuration below:

director d_ftp
	mode nat
	balance source
	option icmpcheck interval 10
	server ftp1 192.168.1.10 weight 10 check
	server ftp2 192.168.1.11 weight 10 check

Click on [OK], then [Apply].


Advanced configuration

Load LVS FTP module

On the GUI, go in the service tab and click on the network service setup icon and add the line below after all the comments:

modprobe ip_vs_ftp

Then restart the network service by clicking on the restart icon .

Flow director configuration

On the GUI, click on Flows tab, then add the configuration below:

flow f_ftp director d_ftp
	match proto tcp dst 192.168.0.100 dstport 20:21
	match proto tcp dst 192.168.0.100 dstport 1024:65535

Click on [OK], then [Apply].

LB Layer 4 configuration

On the GUI, click on LB Layer 4 tab, then add the configuration below:

director d_ftp
	mode nat
	balance roundrobin
	option icmpcheck interval 10
	server ftp1 192.168.1.10 weight 10 check
	server ftp2 192.168.1.11 weight 10 check

Click on [OK], then [Apply].