Dhcpd failover not working

[frooop]

I got 2 pfsense VMs running (failover is needed to able to update the firewall without a downtime). They are connected like this:

But the DHCP status page shows this on both pfsense vms:
master

backup

Carp works fine as this shows:
master

backup

The only other problem (that might be related) I can see is, that I can't ping from one pfsense to the other on the carp interfaces. A machine connected to the same network can ping both, the virtual ips AND the normal ips.

Any ideas on this?

[jimp]

If the two firewalls are unable to reach each other on every interface then the DHCP daemon can't exchange its lease info on each interface running DHCP. Solve that bit and things should start working.