Multi-WAN failing over to a single connection?

microchip

Hi everyone,

I've got a setup with 3x ADSL routed connections which are load balanced, and work great. If one or two go down, the traffic defaults to the remaining one. Traffic is split fairly evenly to them according to the rules I set, balancing out for one that is slightly slower. So far, so good, runs beautifully quickly.

I also have a backup connection (currently a leased line, but being moved shortly to a 3G connection via a router), which is set up via failover routes for specific traffic. Again, so far, so good.

The majority of traffic is going straight down the load balance gateway, as it'd be expected. However, the situation I'm ideally trying to create is as follows:

If possible, route down one of the three ADSL lines according to load balancer config
If the above isn't possible, route down the backup connection.

The backup connection will be charged for data, so I don't want it using as part of the standard load balancing if at all possible, purely as a last resort if all other connections are down. However, the only way I can see to do this is to either set failover connections which only use one connection at a time rather than load balancing, or to have the interface in the load balancing pool but disable the hardware (which will create a need for human intervention should the main ADSL network go down). Ideally, the option would be there in the dropdowns for the failover to have the load balancer as an option as well as the network cards, but that's obviously not the way it is set up.

Is there a way to transparently fail over from a load balancer to a backup connection without it being used for general traffic unless the main 3 lines are down?

Edited to add: It seems when I disconnect all 3 of the ADSL connections but also have the backup connection in the pool, it doesn't seem to work by itself (i.e. I get timeouts), although it will work when part of the pool and they're all up and running. However, I suspect this may be in no small part down to my configuration - there are 27 entries in the load balancing pool to create an accurate ratio to the ADSL connection speeds (9.5mbit, 9.9mbit and 7.3mbit), to put appropriate quantities of traffic down all three. I could probably simply this down to the 3 connections themselves, with little real impact.

Just realised as I was sat thinking last night - I only have failovers on two of the ADSLs onto each other before the backup line. I'll ensure all of them have failovers, and try the tests again. This may be a simple case of not quite figuring out how to do it with 4 connections…

Note: the above didn't seem to make a difference.

(Using pfSense 1.2.3 final, with 2x LAN connections and 4x WAN connections, all via routers in bridge mode.)

(Apologies if this is mentioned somewhere else, but I couldn't find it when searching.)