Remember, when deploying VM HA in VMware, you need to update the security settings on the port-group that is used by the Infoblox VM's to accept “MAC address changes” and “Forged transmits”. This is so that VMware allows the VM's to have multiple MAC addresses per vNIC (which is needed for Infoblox HA). Documentation here and more data here.

When an HA failover occurs on NIOS, there is an approximate 4-5 second time interval in which the network is adjusted for the new active node and the new passive node. During this failover period, the active node becomes unresponsive. After the new active node comes up on the network, the DNS service loads all Response Policy Zone (RPZ) files if RPZ is configured. The larger the RPZ files, the longer it takes to load them, and the longer it takes the DNS service to start serving DNS. For example, on a TE-1425 with RPZs that contain 15 million resource records, it can take approximately one and a half minutes to start serving DNS.

If your nameserver uses Grid replication to keep internal zones up to date and is not configured to use RPZ, then the delay before the DNS service starts serving DNS is slightly longer that it is for the HA failover itself.

The IP will float between the two LAN2 interfaces, but if you have a network failure on one of the LAN2 interfaces, it won't cause a failover to occur. Only LAN1/HA are guarded for failover.

e.g. If LAN1 is for production and LAN2 is for OOB network, if LAN2 on the active node fails, there is no failover and the OOB network looses access to services on LAN2.