Migration from exchange 2003 to 2010

Hi
Thank for your reply
As budget is stricted, I can not buy a certificate from a professionnal authority.
That's why i need an internal pki
Thanks
Regards,
sim

Yes but you will have to pay more for an internal PKI server than for a cert. They are $89.99 or thereabouts at Godaddy (per year)
A Windows server licence is more than that, and the risks and administrative hassle are just not worth it if you are a beginner in PKI.
If you have iPhones and so on to connect, and need to do Outlook anywhere, publish SharePoint securely, you really need to know what you are doing.

Really it is worth getting $100 per year added to your budget for the time ands sleep you will save.

Thank all for yours reply
According an another forum, some people say me that i need one intern PKI and external PKI as I have a disjoint domain. Is it true ?

You can also change the URLs of your internal servers so they are identical to the external ones then you only need one PKI, and one certificate.

http://nathanwinters.co.uk/2010/05/30/script-to-set-internalurl-and-externalurl-for-all-exchange-2010-virtual-directories/

but thats only helpful if you have one external Certificate. If you use an internal one not only do you publish internal information out but you will get issues with browsers and devices supporting/trusting it

YEs I have a split DNS i.e. domain.internal on the inside and domain.com on the outside
I am not sure to understand ... does I need  one external and internal PKI ?

The certificate you need contains the URLs needed to access the servers:

owa.contoso.com is a typical external URL (public certificate)
the internal one might be something like EX01.contoso.local (could be private certificate)

You can't put the internal URL in an external public certificate because it cannot be validated.
But you can change the URL (not the server name) of the virtual directory used internally as in the link I posted.

So internally you use owa.contoso.com and you can use the external certificate to encrypt both internal and external stuff. You have to add a DNS entry internally for the external URL pointing to the internal server.

Then you only need one public certificate for everything.

ok thanks,

if you are running on planning on running Unified messaging it will need a separate certificate - usually internal as it won't need external access.

If you are planning on following the advice to change the URL's then be warned you will still need to add quite a few names into the certificate which will end up being costly

Thats where having an internal cert to do the inside stuff like autodiscover and containing both netbios and internal FQDN's of the servers on and only use an external cert for anything that needs access externally i.e. OWA

As I said at the beginning a 5 server SAN at Godaddy is $89 per year.