I relatively recently demoted one of our two 2008 domain controller, and added a 2016 DC. We'll call them DC1 (2008) and DC2 (2016).
AD, DNS, DHCP (To an extent) have been fine...but I noticed today that nslookup is searching DC1 and returning "Can't find...".
I went into both DC's and they do not share each others DHCP leases. DC1 has some, and DC2 has the others. I've been fortunate not to have a duplicate address leased, but I'd like to get this straightened out before one is.
Is there a compatibility issue between 2008 and 2016 DHCP i overlooked? I'm not able to set a failover in 2016 to anything less than a 2012 DHCP server.