NLB Clustering

I have Exchange 2007, Barracuda, helpdesk applications, Ect, ect, ect........
These applications use a specific domain controller for directory services,
but when I go to reboot one of many domain controllers, specific network
applications are rendered useless during the reboot.

Example:
Reboot domain controller
Exchange freaks out (does not failover to another DC in the site)
Outlook users Address Book fails
Clients consistanently asked for credentials.


The above is just an example of other applications that cant automatically
fail over to another DC...

IM wondering is NLB can accomidate a better client experience when a domain
controller has to be rebooted. By NLB'ing a virtual IP address and
configuring specific applications to a specific DNS name



-----NLB-----> DC
DNS name ------MAPS TO------> Virtual IP address

-----NLB-----> DC

Above scenario would service LDAP, SLDAP, KERBEROS


Thanks for any feedback...

Hello fixthisbox,


You could make an MSCS cluster of 2 DC, but that is not a good design in
my point of view.

For outlook, you could have offline OAB on outlook.

I guess you have something broken under the wood. could you do netdiag &
dcdiag ?

How many global catalog ? Have you 2 GC at least ?

Does this DC have fsmo roles ? which one ?


Cordialement,
Mathieu Chateau
fr blog: http://www.lotp.fr
en blog: http://lordoftheping.blogspot.com


f> Clients consistanently asked
f>

"fixthisbox" <> wrote in message
news:B2BCA604-084D-47EE-8DC3-...
>I have Exchange 2007, Barracuda, helpdesk applications, Ect, ect,
>ect........
> These applications use a specific domain controller for directory
> services,
> but when I go to reboot one of many domain controllers, specific network
> applications are rendered useless during the reboot.

If you have hard coded the applications to use a specific DC/GC, this is
expected behavior. You need to stop pointing to a specific DC/GC and let the
applications go through the SRV records to identify available DC/GCs through
the basic dynamic process.

> IM wondering is NLB can accomidate a better client experience when a
> domain
> controller has to be rebooted. By NLB'ing a virtual IP address and
> configuring specific applications to a specific DNS name

No. The NLB address is a virtual address and thus can not register itself
properly within DNS and certainly will not create an SRV record that points
to the virtual IP.


--
Russ Kaufmann,
MVP, MCSE: Messaging and Security, MCT, MCITP, MCTS and other stuff

ClusterHelp.com, a Microsoft Certified Gold Partner
Web http://www.clusterhelp.com
Blog http://msmvps.com/clusterhelp