600C HA setup

[rmndublin]

Hi Everyone, 

We have a bit of a strange issue.

We have a 600C and it has 2 routes to the web from the network.

We tried to cluster it to another 600C for full hardware redundancy.

All worked well with the exception of one part.

We have two site to site VPNs in our first device.

On the second device we only had a connection for one of our internet links.

So i set the port to be monitored on the first device, my reading here is if the link drops from that port the second device in the cluster will take over.

When we have the initial 600C in standalone both routes work and both the main and redundant VPNs come up.

~When we cluster the two devices the secondary VPN wont come up, this is connected to the same port in both devices.

We only have our primary link connected to the master device and that works correctly.

Is there any trick to this configuration?

I have read all the documentation and not seen it.

This is not the first Fortigate Cluster i have built but never had this issue before.

Thanks