failover problem

[Mark]

Over the weekend my main DC crashed and my second DC
didnot take over. Exchange was not able to locate a DC
and my second DC is set to be a GC. Is there a reason the
second DC did not take over I have no error messages.
Once the first DC goes down I cannot logon.

 

[Jim Singh]

Make sure the your second DC is infact a Global Catalog server, since the
you need a GC in the forest/domain to process the logon authentication
requests from the client. Exchange also needs a GC to locate the srv dns
records in order to route mail. Also check that there are no firewals in
between that are blocking 389 LDAP, 53 Dns, and 25 smtp ports are open,
since you alteast require these ports to be open for communication.

-Jim

 

[ptwilliams]

If the first DC is a DNS server and the second isn't then there's your
answer. If both DCs are DNS servers, but you are only configuring the
clients to point to one, then when that fails so does your AD.

You should always configure an alternate DNS server.

Are you're clients pointing to both DCs for DNS?

--

Paul Williams
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Make sure the your second DC is infact a Global Catalog server, since the
you need a GC in the forest/domain to process the logon authentication
requests from the client. Exchange also needs a GC to locate the srv dns
records in order to route mail. Also check that there are no firewals in
between that are blocking 389 LDAP, 53 Dns, and 25 smtp ports are open,
since you alteast require these ports to be open for communication.

-Jim

 

[Mark]

Thanks for the quick responce but both DC's are DNs
servers and they are setup on the clients as firrst and
second.

 

[ptwilliams]

How long are you waiting? Outlook, and probably Exchange (I'm about to
start learning exchange so don't know) cache the GC record. Some programs
will do a lookup and be OK, others will have cached it and will take some
time (30 minutes come to mind) before they failover.

--

Paul Williams
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Join us in our new forums!
http://forums.msresource.net
_________________________________________


Thanks for the quick responce but both DC's are DNs
servers and they are setup on the clients as firrst and
second.