This Knowledgebase article provides information about the requirement to unplug network cables during installation of Orion Failover Engine on Windows Server 2008
When installing Orion Failover Engine on a Windows Server 2008, SolarWinds recommends that when instructed to do so during the installation process, the Admin should unplug the network cables. This is required when restoring the backup file taken from the primary server to the secondary server.
Network cables are unplugged to avoid IP address and name conflicts with the production server since the packet filter is not installed on the secondary server until later in the installation process. During the restore process, the IP address and name are copied to the secondary server and without unplugging the cables, a conflict will exist.
After the step in the installation process where the packet filter is installed on the secondary server's principal (public) NIC, the Admin will be directed to plug the network cables back in.
Note: The NICs should not be just disabled – if they are only disabled during the Orion Failover Engine setup, the packet filter will not be installed resulting in the server being configured as passive but not filtered because the component that performs filtering will not be present.
SolarWinds Orion Failover Engine All Versions