We are about to go through an Active Directory upgrade from W2k AD to W2k3 AD. I've read various documents from Microsoft and gone through the checklists as far as verifying current replication is happening correctly, DNS resolution, etc. Here is a brief summary of our environment followed by some key questions that we would like to advice on (best practices and/or real-world upgrade experiences instead of MS's document experience) :-)
Company itself - 2 main data center sites with approx 20 remote sites. DCs exist only at the main sites.
5 DCs in total all running Windows 2000 SP4.
1 DC in the parent (w2k.pardomain.com)
2 DCs in south data center site (sdc1.childdom.pardomain.com & sdc2.childdom.pardomain.com)
2 DCs in north data center site (ndc1.childdom.pardomain.com & ndc2.childdom.pardomain.com)
Currently in AD/Sites we have two main sites setup a North and South (ndcx assigned to North, sdcx, w2k assigned to South).
DNS is running on all DCs.
DHCP is running on (w2k for the South region) and (ndc1 for the North region)
We have new hardware for all 5 DCs and the end result is that we will have all DCs on the new hardware with the same computer names and IP Addresses.
Various questions we have are:
1. What would be considered the best practice for upgrading our domain. Do we need to do an actual server OS upgrade or can we just prepare the domain for 2003AD, install 2003 on the new servers and dcpromo them in followed by dcpromo'ing the old 2000AD servers out?
2. Once we have w2k upgraded, in the interim we will have a mixed configuration (2003AD and 2000AD) while we are working on converting the others servers, should we expect any DNS related issues in regards to clients resolving internal resources? (other than a server being offline, obviously)
3. For DHCP, is it possible to export the current 2000 DHCP configuration and import that into 2003 DHCP?
4. For DNS, (same as 3.) is it possible to export/import from 2000 to 2003