Change to internal namespace

[Dan Snape]

Hi All,

As part of migrating from Exchange 2010 to Exchange 2016, our customer will also be moving to implementing split DNS (going from "domain.local" with a certificate issued by an internal CA to "domain.com" with a certificate issued by a 3rd party CA). Is anyone able to provide some advice on doing this in a way that minimises the impacts to clients, and also provide some information on what the impact to clients we may experience when performing this change.

Thanks.

Dan

[#2 · Accepted solution]

Normally you would have to reduce the TTL of DNS resources records in question when changing IP-adresses or host names. But as you are changing the namespace, the clients would have to pickup the new urls provided by AutoDiscover. AutoDiscover caches the data requested for a single user. So a change in vDir url configuration will be picked up by clients immediately.

For Exchange 2010, restart the AutoD application pool

For Exchange 2013+ you can use the follow two one-liners to restart the AutoD application and the service.

Get-ExchangeServer | ? { $_.AdminDisplayVersion -like '*15.*'} | % { Invoke-Command -ComputerName $_.Name -ScriptBlock {Restart-WebAppPool MSExchangeAutodiscoverAppPool } }

Get-ExchangeServer | ? { $_.AdminDisplayVersion -like '*15.*'} | % { Invoke-Command -ComputerName $_.Name -ScriptBlock {Restart-Service MSExchangeServiceHost } }

In addtion, these changes should be implemented during off-hours.

Cheers,

Thomas

[#3]

In addition to what Thomas said, you can also check the Exchange Team blog about Namespace Planning: 

https://blogs.technet.microsoft.com/exchange/2015/10/06/namespace-planning-in-exchange-2016/

Regards,