CARP failover setup using VirtualBox VMs

[dhatz]

Is anyone successfully using CARP failover in VirtualBox VMs? I seem to be having problems using the latest VirtualBox 4.1.12 on a Ubuntu 11.04 host.

My test CARP setup consists of 2 identical pfsense VMs with 3 NICs each, connected using the 3 different technologies (bridged, host-only, internal) offered by VBox:

WAN Adapter 1: Intel PRO/1000 T Server (Bridged adapter, eth0)
LAN Adapter 2: Intel PRO/1000 T Server (Host-only adapter, 'vboxnet2')
SYNC Adapter 3: Intel PRO/1000 T Server (Internal network, 'carpsync')

The sync seems to work (e.g. configuration changes are replicated to slave, also when I disconnect the master VM then "Status -> CARP (failover)" on the slave shows that it assumes master role etc), however the shared CARP VIPs for LAN and WAN don't respond anymore once the slave takes over.

The pfsense book & wiki offer suggestions for running CARP on VMware's vSwitch, but I found nothing about VBox and there's very little documentation about the behavior of the software-switches which VBox implements (host-only, internal).

[dhatz]

Well, to followup my own post, it seems that setting "Promiscuous mode: Allow All" on the relevant interfaces of the VM solved the issue for both bridged and host-only types of net. Now the CARP shared IPs fail-over as expected.

[jimp]

Thanks for tracking that down, I added it to: http://doc.pfsense.org/index.php/CARP_Configuration_Troubleshooting