When trying to configure Failover no matter what sub-network I try to configure in the virtual IP I always receive the following message.

"The entered Virtual IP is in the same subnetwork as one of the network interfaces or Virtual IPs that already exist in the system.
It is recommend to use IP that has a unique subnetwork class and is not used in any other place in your configuration.
Do you want to continue?"

If I continue then the web interface also displays a warning that says the following:
"Warning
It is recommend to set a Virtual IP that is in different subnetwork than physical and Virtual IPs on this machine."

So my question is, is this same subnet detection broken or is there actually some combination of subnets that work?

I have tried having an interface on the 10.x.x.x with netmasks of /16 and /24 mixed with the 192.x.x.x and it always complains about them being on the same subnet.

Can someone tell me what I might be doing wrong?

For example, I have eth0 as 192.168.137.171 and eth1 as 10.100.100.4 and a Virtual IP on failover eth1 as 192.168.101.4 and it still complains? I just updated to the latest firmware ( 6.0up85.xxxx.5794 2011-10-07 b5794) to see if that made any difference but it did not?

Can anyone shed some light on this?

thanks,
-Tomas