Exchange 2007 EMC points to a remote Active Directory server

Hello. We have Exchange 2007, one DC, and a backup DC in our LAN. We also
have a backup DC in our remote office which is connected with a T1. We
always notice that when we open EMC, it takes a long time to come up with
the main EMC screen. Today, while my co-admin was adding a new contact, the
T1 line to our remote office went down and he received an error from EMC:
"Error: An Active Directory error 0x51 occurred while trying to check server
'bdc.mydomain.local:389' suitability: 'The LDAP server is unavailable.'".
What can we do to make EMC, or Exchange 2007, query the DC or backup DC in
our local LAN, instead of going out to a remote BDC?

Thanks in advance.

Do you have Sites and Services set up with a site for the remote DC?
Anthony
http://www.airdesk.com


"C C" <(E-Mail Removed)> wrote in message
news:uis#(E-Mail Removed)...
> Hello. We have Exchange 2007, one DC, and a backup DC in our LAN. We
> also have a backup DC in our remote office which is connected with a T1.
> We always notice that when we open EMC, it takes a long time to come up
> with the main EMC screen. Today, while my co-admin was adding a new
> contact, the T1 line to our remote office went down and he received an
> error from EMC: "Error: An Active Directory error 0x51 occurred while
> trying to check server 'bdc.mydomain.local:389' suitability: 'The LDAP
> server is unavailable.'". What can we do to make EMC, or Exchange 2007,
> query the DC or backup DC in our local LAN, instead of going out to a
> remote BDC?
>
> Thanks in advance.
>

"C C" <(E-Mail Removed)> wrote in message
news:uis%(E-Mail Removed)...
> Hello. We have Exchange 2007, one DC, and a backup DC in our LAN. We
> also have a backup DC in our remote office which is connected with a T1.
> We always notice that when we open EMC, it takes a long time to come up
> with the main EMC screen. Today, while my co-admin was adding a new
> contact, the T1 line to our remote office went down and he received an
> error from EMC: "Error: An Active Directory error 0x51 occurred while
> trying to check server 'bdc.mydomain.local:389' suitability: 'The LDAP
> server is unavailable.'". What can we do to make EMC, or Exchange 2007,
> query the DC or backup DC in our local LAN, instead of going out to a
> remote BDC?
>
> Thanks in advance.
>

This is actually an Exchange question for the Exchange newsgroups, but I
will be able to assist.

First, there is no such thing as a BDC in Windows 2000, 2003 or 2008. They
are all replica DCs. A BDC is a legacy NT4 term.

As for which DC the EMC is using, go into the EMC. And opening the EMC is
slow anyway, whether using a nearby DC or a remote DC. Then on the top left,
click on "Organization Configuration." To the far right, you will see
"Modify Configuration Domain Controller." Change it to the local DC.

You may want to also go into Server Configuration, click on the severname in
the top middle of the results pane, then click on Properties in the far
right tasks paneClick on System Settings tab, and make sure it picks up all
DCs in your infrastructure. You can't change anything here, but this is to
make sure that it picks them up.

Otherwise, if you continue to have problems, the main thing that causes
99.99999% problems in AD are:
1. Using an ISP's DNS server in IP properties of ANY machine in a domain
(DCs, clients, etc).
2. AD Domain name is single label name (domain vs the required minimum of
domain.com, domain.local, etc)
3. The DC or any DC is multihomed (more than one NIC and they are not
teamed, or more than one IP)

Any of the three above will cause MAJOR issues with AD.

--
Ace

This posting is provided "AS-IS" with no warranties or guarantees and
confers no rights.

Ace Fekay, MCSE 2003 & 2000, MCSA 2003 & 2000, MCSA Messaging, MCT
Microsoft Certified Trainer
(E-Mail Removed)

For urgent issues, you may want to contact Microsoft PSS directly. Please
check http://support.microsoft.com for regional support phone numbers.

That's sure what it sounds like. Sites are not correctly setup.

"Anthony [MVP]" <(E-Mail Removed)> wrote in message
news:uKfCH#(E-Mail Removed)...
> Do you have Sites and Services set up with a site for the remote DC?
> Anthony
> http://www.airdesk.com
>
>
> "C C" <(E-Mail Removed)> wrote in message
> news:uis#(E-Mail Removed)...
>> Hello. We have Exchange 2007, one DC, and a backup DC in our LAN. We
>> also have a backup DC in our remote office which is connected with a T1.
>> We always notice that when we open EMC, it takes a long time to come up
>> with the main EMC screen. Today, while my co-admin was adding a new
>> contact, the T1 line to our remote office went down and he received an
>> error from EMC: "Error: An Active Directory error 0x51 occurred while
>> trying to check server 'bdc.mydomain.local:389' suitability: 'The LDAP
>> server is unavailable.'". What can we do to make EMC, or Exchange 2007,
>> query the DC or backup DC in our local LAN, instead of going out to a
>> remote BDC?
>>
>> Thanks in advance.
>>

"Martin Blackstone [MVP]" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
> That's sure what it sounds like. Sites are not correctly setup.

Good point. If Sites were setup and setup properly, the EMC would have
selected a DC in its own Site.

Ace

Hello C,

Make sure AD sits and services is reflecting the physical topology of your
network. Also it should be configured to use the site internal DNS server
as preferred and not others on the NIC.

http://technet.microsoft.com/en-us/l.../cc755768.aspx

Best regards

Meinolf Weber
Disclaimer: This posting is provided "AS IS" with no warranties, and confers
no rights.
** Please do NOT email, only reply to Newsgroups
** HELP us help YOU!!! http://www.blakjak.demon.co.uk/mul_crss.htm


> Hello. We have Exchange 2007, one DC, and a backup DC in our LAN. We
> also have a backup DC in our remote office which is connected with a
> T1. We always notice that when we open EMC, it takes a long time to
> come up with the main EMC screen. Today, while my co-admin was adding
> a new contact, the T1 line to our remote office went down and he
> received an error from EMC: "Error: An Active Directory error 0x51
> occurred while trying to check server 'bdc.mydomain.local:389'
> suitability: 'The LDAP server is unavailable.'". What can we do to
> make EMC, or Exchange 2007, query the DC or backup DC in our local
> LAN, instead of going out to a remote BDC?
>
> Thanks in advance.
>

Apparently, AD Sites and Services was not setup correctly in our Domain.
How is this set up? We have been running with this for a long time and now
Exchange 2007 EMC insists on going to a remote DC. We only have EX2K7 for 3
months. We did not have this problem (I don't recall) when we were using
Ex2K3.

Thanks in advance.

"Ace Fekay [Microsoft Certified Trainer]" <(E-Mail Removed)>
wrote in message news:(E-Mail Removed)...
> "Martin Blackstone [MVP]" <(E-Mail Removed)> wrote in message
> news:(E-Mail Removed)...
>> That's sure what it sounds like. Sites are not correctly setup.
>
> Good point. If Sites were setup and setup properly, the EMC would have
> selected a DC in its own Site.
>
> Ace
>
>

"C C" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
> Apparently, AD Sites and Services was not setup correctly in our Domain.
> How is this set up? We have been running with this for a long time and
> now Exchange 2007 EMC insists on going to a remote DC. We only have EX2K7
> for 3 months. We did not have this problem (I don't recall) when we were
> using Ex2K3.
>
> Thanks in advance.

Exchange 2007 exclusively uses AD site definitions for DS resources, whereas
Exchange 2003 does not. However, Exchange 2003 DC would pick up on any DC in
it's site and show up in the ESM, Dir service tab, as availalbe for use, but
the ESM would connect to a DC defined in the DS tab in it's own Site. You
may not have noticed it, but Exchange 2007 is more sensitive to it (loosely
put).

Ace