Pros and cons of multiple domain controllers

[Andrew M. Saucci, Jr.]

On a relatively small, single-site network of about 50 XP/2000
workstations and six Windows 2003 servers, what are the pros and cons of
multiple domain controllers as opposed to a single domain controller? We run
imaging software on the servers, so I'm not too concerned about having to
spend lots of time restoring Active Directory from a tape backup (though we
have that too if necessary). Users can log on with cached credentials if the
DC is temporarily unavailable. Am I missing anything? Having had some
negative experiences with AD replication issues, I am concerned about
introducing those into what is now a fairly simple topology. On the other
hand, some redundancy is always appealing.

[Lanwench [MVP - Exchange]]

Post by Andrew M. Saucci, Jr.
On a relatively small, single-site network of about 50 XP/2000
workstations and six Windows 2003 servers, what are the pros and cons
of multiple domain controllers as opposed to a single domain
controller? We run imaging software on the servers, so I'm not too
concerned about having to spend lots of time restoring Active
Directory from a tape backup (though we have that too if necessary).
Users can log on with cached credentials if the DC is temporarily
unavailable. Am I missing anything? Having had some negative
experiences with AD replication issues, I am concerned about
introducing those into what is now a fairly simple topology. On the
other hand, some redundancy is always appealing.

Pros? Redundancy and easier disaster recovery if your existing server goes
belly up. Speed of authentication for your users. Etc.

Cons? None, really, if you set it up right. It's pretty easy. Not sure what
prolems you had in the past wiht AD replication, but in your small network,
I can't imagine it being a real issue.

You should always have at least two domain controllers if possible....and
you aren't a single server shop, so it's possible.