Exchange 2007 to 2013 migration

I have an exchange 2007 and I am planning to move to 2013
I have created a new internal public DNZ zone to apply new type of certificates that only support public in Exchange 2013.
My exchange 2007 have valid old certificate that support .local and it expires on October
What happends if I apply new in Exchange 2013 to all vitual directory autodiscover, OWA, webservices internal and external, Active sync, autodiscover withe set-clientAccessServer.
Would this stop CAS based communucation to all users mailboxes in 2007.
Would I be able to switch back on old exchange certificate, if I get any issues
pchettriIT DirectorAsked:
Who is Participating?

[Product update] Infrastructure Analysis Tool is now available with Business Accounts.Learn More

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.

Manikandan NarayanswamySecurity Specialist & IBM Security GuardiumCommented:

You can create a new certificate with below entries on it.,
 & Apply the certificate in exchange 2007 & 2013. Assign a separate Public IP address on a 2013 server. So any users who is connecting to new 2013 OWA server. If his mailbox exist on 2007 a silent redirection will take place to Modify the public DNS / to point to exchange 2013 & to point to exchange 2007. Your exchange 2007 outlook anywhere authentication must be set to NTLM. Then configure the exchange 2007 & 2013 URL using Set-ClientAccessServer cmdlet. If you follow this way you won't face any issues this is proper migration steps towards exchange 2013.

MASEE Solution Guide - Technical Dept HeadCommented:
Hi pchettri,
Please check this for detailed steps to migrate from Exchange2007 to Exchange2013.

As commented above you need and additional public IP.
And you need to add as a SAN in your certificate.
When you install Exchange2013 in your organization you should point your and to the newly installed Exchange2013 server and create an additional A record "" in both internal and external DNS which points to Exchange2007.

And you have to set your internal and external URLs the same.

Ping these A records from your internal network and make sure it returns your Exchange2013 server internal IP
2.  (i.e. common name)

Ping which should return your Exchange 2007 server internal IP

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
pchettriIT DirectorAuthor Commented:
what would be list of A records that I would need to add in public DNS zone created internally to resolve the public name on virtual directories? I am sure it cannot have public IP for mailhost. I presume I have create A record of mail host and point to internal IP address
IT Pros Agree: AI and Machine Learning Key

We’d all like to think our company’s data is well protected, but when you ask IT professionals they admit the data probably is not as safe as it could be.

MASEE Solution Guide - Technical Dept HeadCommented:
These A records you have to create in zone in your internal DNS server
1.autodiscover          (Points to Exchange2013 internal IP)
2. mail                       (i.e. common name  which points to Exchange2013 internal IP)
3. legacy                   (Points to Exchange 2007 server internal IP )
MASEE Solution Guide - Technical Dept HeadCommented:
You need the same A records in your external DNS as well
pchettriIT DirectorAuthor Commented:
Once I apply new certificates in Exchange 2013 and find any issues. Would I be able to switch back to my exchange as CAS server? If I get any issues resolving certificate with public based DNS using new certificate in Exchange 2013
MASEE Solution Guide - Technical Dept HeadCommented:
If you follow the above article and if you configured DNS properly you will not have any issues.

Ensure you have these A records in DNS

Internal DNS server
1.autodiscover          (Points to Exchange2013 internal IP)
2. mail                       (i.e. common name  which points to Exchange2013 internal IP)
3. legacy                   (Points to Exchange 2007 server internal IP )

External DNS server
1.autodiscover          (Points to Exchange2013 External IP)
2. mail                       (i.e. common name  which points to Exchange2013 external IP)
3. legacy                   (Points to Exchange 2007 server external IP )

For testing move your mailbox to Exchange2013. Add a host entry in your laptop/computer and try to open outlook and check. Let me know if you have issue.
Create a test account in Ex2007 and try to access that test account from the same computer which you added host entry and that check for errors. if both users working fine without issue change your DNS entries in your (i.e. and DNS server (both internal and external) point to  Exchange2013

Check this on how to add host entry.
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.