I used the Export-Dhcpserver and Import-Dhcp server cmdlets to easily move my 2008 DHCP configuration to 2012. The 2012 server is working just fine in place of the 2008 server.
I'm now trying to configure failover. None of the imported scopes let me do it - the option to configure failover is not there. If I create a new scope from scratch, the configure failover option is there. Is there something about imported scopes that I have to change?