We're experimenting with what VMWare called a "Fully Collapsed DMZ" on blade centre. Basically our DMZ goes straight into a vSwitch and all the security appliances are virtualised.
I've spent days reading up about why this is a good idea and why it's a bad idea, what needs to be done to make it safe, etc, but the one thing I'm having trouble finding is information regarding the best fault tolerance method.
Our edge firewall of choice is pfSense which supports CARP. We've got 10 blades in the cluster, so it's quite feasable to have two or even three pfSense firewalls with VMWare HA enabled and configured internally with CARP that take over eachother in the event of a blade failure. But this seems like a lot of administrative overhead and I'm an un-trusting kind of guy, so it means that I'll be logging into multiple firewalls every week to make sure that all our rules etc have mirrored.
But why bother with CARP when VMWare's FT (even with its single vCPU shortfall) will provide all the features of CARP and as afar as I can tell, less management, stress and concern for my job.
Is there any compelling reason to use CARP over FT, or vice versa for a software-based firewall?