DC goes down, so does Exchange?

  • Thread starter Thread starter mark
  • Start date Start date
M

mark

Hello all, I have two Windows 2000 advanced servers, both
are domain controllers with AD running. When I reboot one
of the domain controllers, our exchange server, which is
running on a completely different member server, also
becomes unavailable until the domain controller comes
back online. I thought having a second domain controller
would prevent this from happening, but it does not. Does
anybody know why this happens and how i can stop it.
Thank you!!
 
What are you DNS settings of the exchange server. Is the server you are
rebooting the PDC emulator? What version of Exchange? Does this only
happen when you reboot a particular DC or if any one of them is rebooted?
Answer these questions and i could better offer some suggestions.

Regards

Paul McGuire
 
Three reasons are likely with Exchange 2000:

1) Loss of authentication for clients
2) Loss of GC (global catalog)
3) Loss of DNS server (DCs are frequently DNS also)

Clients must find, generally using DNS, the Exchange server
a DC (and perhaps a GC) and the Exchange 2000 server
substituted the Global Catalog for the prior GAL
(Global Address List).

Solutions include adding another DC/DNS with a GC
included. Make the Exchange server (and clients) "DNS
clients" of more than one DNS server to avoid single-point
DNS failure.

You can implement a GC on an existing DC in AD Sites
and Services.

Additional reasons include, the DC is also a router or
even another service (e.g., WINS for legacy clients) that
when down prevents the clients from reaching or finding
the Exchange server or this server from finding other email
servers....
 
The DC that goes down is the ONLY gc server that i have.
Our other domain controller is not a gc server. Can i
have both of the dc's as being gc servers? Is there any
downfall to this? We are talking about exchange 2000.
 
Thanks Herb, can I have multiple gc servers in the same
domain? I found the setting to allow the second dc to
become a gc, is it as simple as checking the box off and
rebooting the dc? Thanks for your help!
 
You can have as many GCs as you wish -- for single
site, single domain Forests many people recommend
all DCs become GCs.

The main (only) negative about too many additional GCs
is in large forests, as the GC holds a PORTION of the info
for every object in the FOREST while ordinary DCs (and
all GCs) hold all the information for the objects of that single
domain --only.

Note that in small domains/forests you generally have relatively
fewer DCs also, so it is usually more important to gain fault
tolerance of the GC than to worry about a "little" extra replication.

So with one domain, or a small forest, there is little negative
impact to all DCs becoming GCs.

Those with 100,000 of users and other objects would not
wish to do this in many/most cases.
 
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