OWA 2010 Redirect to OWA 2003 Unspecified Error

I've just installed Exchange 2010 CAS server.  In my enviroment we'll temporarily co-exist Exchange 2010 and 2003 due to the fact that majority of user's email will take time to be moved over to 2010.  I need help.  I ran the OWAVirtualDirectory cmdlet to redirect from CAS to OWA2003.  I can see in the url that we are hitting our OWA2003, however, I am getting an "Unspecified Error" message with a blank page at url https://domain.com/exchweb/bin/auth/owaauth.dll.  Anyone have experience this?  Help!
Who is Participating?
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

Glen KnightCommented:
Do you have access to both URL's from the internet?

Exchange 2010 doesn't proxy for Exchange 2003 therefore you need to have 2 IP's and 2 hostnames for example:

https://exchange2010.domainname.com/owa and https://legactexchange.domainname.com

konvodAuthor Commented:
yes we have dns entries for

they are also listed on our uc cert.
i should make a correction to my question... i am getting UNSPECIFIED ERROR at https://legacy.domain.com/exchweb/bin/auth/owaauth.dll.  not https://domain.com/exchweb/bin/auth/owaauth.dll.
Glen KnightCommented:
so from outside your network can you navigate to https://legacy.domain.com/exchange and login?
Price Your IT Services for Profit

Managed service contracts are great - when they're making you money. Yes, you’re getting paid monthly, but is it actually profitable? Learn to calculate your hourly overhead burden so you can master your IT services pricing strategy.

hi demazter
ya from outside u can use  https://legacy.domain.com/exchange and login if it has proper DNS entry

Hi konvod
Are u able to access the OWA for 2010 users properly or not ??
konvodAuthor Commented:
yes i am able to log into owa 2010 properly.
Glen KnightCommented:
@praveenkumare_sp > I was actually trying to identify if both URL's were accessible from the internet which they need to be if this is going to work.

Are you able to access the 2003 server using the legacy URL from ourside of your network?
Could you share what is the command that u used for setting the owa virtual directory , i am refering to the line " I ran the OWAVirtualDirectory cmdlet to redirect from CAS to OWA2003."

and also specify whether it is a FE 2003 server
konvodAuthor Commented:
@demazter. I am able to access 2003 outside of network

@praveenkumare.  Here is my cmdlet:
Set-OWAVirtualDirectory -Identity "CAS\owa (Default Web Site)" -ExternalURL https://webmail.domain.com/OWA -Exchange2003URL https://legacy.domain.com/exchange
The command seems correct

Check the authentication on the 2003 server ,  whether you have FBA or not ?

Run this command Get-OWAVirtualDirectory -Identity "CAS\owa (Default Web Site)"  and see whether the Exchange2003Url attribute has the correct information.
konvodAuthor Commented:
it is using fba.
yes info for virtual directory is correct.
Glen KnightCommented:
FBA should be disabled on the 2003 server for the redirect to function correctly.
FBA has to be enabled for the silent redirection to work , If you disable FBA we might start recieving http 500 error

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
If the url https://legacy.domain.com/exchange is available externally and if users are able to login to that directly and
if you have set this commnad Set-OWAVirtualDirectory -Identity "CAS\owa (Default Web Site)" -ExternalURL https://webmail.domain.com/OWA -Exchange2003URL https://legacy.domain.com/exchange  and
If you have FBA the configuration is correct

Just double check the above settings again
konvodAuthor Commented:
I've enabled FBA in OWA 2003 and it resolved the issue.  Thanks to all the valuable help!!
You are welcome :)
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today

From novice to tech pro — start learning today.