Our network is currently comprised of Windows 2003 servers and Windows XP workstations. Within the next few months, our PC deployment group plans to start rolling out workstations with Windows 7. In addition, one of our vendors just sent us an e-mail stating that their next version of the software due out in the next few months will require Windows 2008 and no longer support Windows 2003.
Now, our system administrator is telling us that Windows 7 and Windows 2008 will interfere with our network because our main servers (Active Directory, DNS, etc) are Windows 2003 servers. They will force master browser elections and so on...
Is he correct? Will they interfere? I would have thought this would be a larger issue if this was indeed the case. Links to any documentation regarding this matter would be appreciated.
In one way, introducing Windows 2008 and Windows 7 will interfere with master browser elections in NetBIOS. That being said, this is not an issue for many different reasons.
First, you need to know that master browser selection is based on domain controller status and Windows version (this is where 2008 comes in to play). The PDC emulator will always win master elections no matter what OS level they are at. For broadcast domains where the PDC emulator role is not running, domain controllers will try to become the master. Finally, if no DC is available then the highest Windows version will win the election.
With that being said, very few applications rely on NetBIOS these days. Almost all Microsoft applications and third party applications will resolve through DNS, not NetBIOS.
Additionally, anyone relying on NetBIOS will have WINS deployed on the network. WINS removes the reliance on master browsers and allows NetBIOS to operate across subnets. Windows clients configured with a WINS server will default to H-nodes which means they query WINS before doing a broadcast for name resolution.
Once that is all said and done, if you still needed NetBIOS, did not run WINS and had no domain controllers on a network, introducing Windows 2008 or Windows 7 would allow them to become master browsers on your network. Even if that were the case, Windows 2008 and Windows 7 will happily act as master browsers without any negative effects. If you still didn't want that to occur, then simply set the MaintainServerList and IsDomainMaster to No and False respectively. http://technet.microsoft.com/en-us/library/cc959923.aspx
/me steps out of time machine...
Provided your new servers are only member servers and nothing fundamental to the operation of your domain, you won't have any nonsense at all. Speaking from experience, my first 2008 R2 file server went into my environment (which was totally 2003) without a hitch.
Even if you decided your new 2008 servers were going to start hosting Active Directory and all its associated stuff, it would cause you no more real grief than any other major change like this on 2003.
People knock Microsoft so often, but they really DO go to ridiculous lengths to ensure application compatibility. This is especially true of Microsoft software, but still a great deal of compatibility work goes into ensuring your legacy apps keep working too. After all, if stuff didn't work with newer versions of Windows, what's the point of upgrading at all?
Is your sysadmin stuck in 1996? He's worried about Master Browser elections in a Win2k3 AD? Ask him for specific documented problems - it's possible that you may have some serious legacy applications, but if that's the case you should have a WINS infrastructure and lock down the NetBIOS NodeType on the machines with GPOs (or maybe DHCP.)
Or he may be referring to something else when you say he said "...and so on..." ; like I said, press him for details and then research those details. Because in general, the scenario you describe is not a problem.
We have run pretty much all flavors of windows servers and clients in a 2003 level domain. No problems related to that at all. Separating our group from another we set up a separate 2008 domain and migrated 2003 R2 and 2008 servers to it. No issues there either. In my experience AD is one of the things that MS has got right.
Migrating AD from 2003 to 2008/2008 R2 is well documented and MS and sites all over has lots of articles and how-to's on that. I recommend you dig out some nice documentation and get up to date.
Master Browser only affect NetBIOS resolution, which should not be an issue in an Active Directory environment in the first place, as you should be relying on DNS instead of NetBIOS. If you do not trust DNS somehow, you should set up WINS server (maybe on the domain controller) and point all your computers to the WINS server via DHCP.
No matter what, you want to replace your master browsers with WINS server to cut down on vulnerabilities and network broadcast (bad security + bad network performance). My network has Windows 2003, Windows 2008, XP, Vista and 7, and we do not have any issues.