Xchange!

LegacyDN and X500

'Ary' — Mon, 25 Mar 2013 18:23:26 GMT

Being someone who did not have a chance to work with Exchange prior to Exchange 2003, there are aspects of Exchange, even today, that seem to stem from back in time, some that I don't fully understand in terms of how do they play and why. On that list, Legacy Exchange DN and X500 happen to be two items.

Both LegExDN and X500 intrigued me for quite some time now. But not any more I guess!

Just a few minutes ago during a random innocuous search, I stumbled on this blog post by the product team from back in time about LegDN and X500 addresses, finally ending a small part of my larger quest.

http://blogs.technet.com/b/exchange/archive/2004/03/24/95451.aspx

It gives the background and explains why LegDN is so important and how X500 works.

My key takeaway was that Outlook internally uses LegDN for mail routing. I kind of understood this before but I definitely have a better understanding now.

Happy reading!

-Ary

Microsoft Connectivity Analyzer (MCA)

'Ary' — Sat, 16 Mar 2013 13:04:37 GMT

Its been some time that administrators wanted a tool similar to the Exchange Remote connectivity Analyzer (EXRCA) to check for connectivity issues internally within their environment. Well, guess what? There is one available now, ready for you to download. Its called the Microsoft Connectivity Analyzer (MCA).

Please check the official product team's announcement here:

http://blogs.technet.com/b/exchange/archive/2013/03/11/announcing-microsoft-connectivity-analyzer-mca-1-0-and-microsoft-remote-connectivity-analyzer-rca-2-1.aspx

A point worth mentioning. This tool goes along with the already existing Microsoft Exchange Remote Connectivity Analyzer (EXRCA) which is also celebrating a new version release V2.1.

Ary

Outlook, Public folders and "Your Exchange admin made a change..."

'Ary' — Sat, 16 Mar 2013 12:46:00 GMT

Recently, I was at a customer who had end users experiencing the much familiar " Your Administrator has made a change. Please restart your outlook" prompt. There could be various reasons why this could happen but what intrigued me in this particular instant was that the customer was seeing this outlook prompt whenever they failed their DAG members over.

After some quizzing, here is what I understood about the environment.

All their Exchange servers were multirole servers with MBX-CAS-HT roles installed on them.
Since these servers had CAS role installed on them, these servers were part of the CAS Array as well.
One of the servers in each site also had a public folder replica homed on it.
Clients were mostly using Outlook 2010.

Okay, looks like a pretty clean environment to me... what is causing the problem?

Good question! Turns out that hosting a public folder replica on one of the CAS servers that's a part of the CAS Array is what is causing the problem.

Here's the explanation:

" This behavior is expected when a public folder exists on a multirole server that is part of the Exchange Server 2010 CAS array.This issue occurs because the
VIP of the CAS array is being returned to the client instead of the hosting server.

The problem arises when an Outlook client connects to the CAS array. Initially, if outlook connects to the CAS array member that contains the PF role, then Outlook converges all
connections and displays both the Public and Private logons as one single connection (the CAS array name). When the Client re-connects and gets connected to a CAS array member
that does not have the PF server, then it gives a wrong server response from Exchange, Outlook in its reconnect logic cannot follow the redirection to the correct PF server name and has to reconfigure itself through a profile refresh. Hence the users get prompted with a " Restart your Outlook" message. "

So what can we do about it if we are currently encountering this issue in our environment? Presently to work around this problem and avoid the prompt, the suggested approach is to move your public folder replicas to a server that is not part of the CAS Array.

Also something to try is replicating your public folders to all the CAS servers that are part of the CAS Array. I am yet to try this approach so please test it first before implementing in production.

-Ary

So What's changed in Exchange 2013?

'Ary' — Tue, 15 Jan 2013 03:02:00 GMT

Now that Exchange 2013 has been GA for sometime now, I am sure some of you must have already tried playing with it. Although Exchange 2013 cannot be in implemented to co-exist with Exchange 2007 or Exchange 2010 yet (the co-existence SP for Exchange 2010 and RU for Exchange 2007 are expected to be released this quarter as per an Exchange Team announcement), you can implement it as a greenfield environment or in your test lab and start plying with it. Although greenfield Exchange 2013 might not be an option favored by many, testing and familiarizing yourself with Exchange 2013 is certainly a great opportunity while we await the co-existence components release.

I quickly wanted to list some of the changes in Exchange 2013 in comparison so Exchange 2010 and 2007.

1. Outlook now connects to the CAS servers only using RPC/HTTPS (Outlook Anywhere).

2. "RPCClientAccessServer" attribute is now deprecated. However, the RPC Client Access Array introduced in EX2010 still exists in EX2013 and needs a load balancer to load balance the client connections. That said, the recommended load balancing method in Exchange 2013 is IP-based only . The CAS servers take care of the session affinity for you. Hurray! no more struggles to get the load balancer configuration right!

3. There are only 2 roles available in EX2013 - 1. Client Access Server role 2. Mailbox Server Role

4. Exchange Administration Console (EAC) is the new administration console in EX2013. It is now a web based console.

5. The Hub Transport server role functionality that existed in Ex2010 and EX2007 has been now moved into the Mailbox Server role.

6. The CAS server is Ex2013 is a stateless proxy that essentially proxies all the protocols back to the MBX server. Your client connections are all now held on the mailbox server unlike on the CAS server in EX2010. Also the Outlook connection point is now the Mailbox GUID of the particular user and not the Exchange server name. This ensures that the end users no longer get the "Your Administrator has made a change to your mailbox. Please restart your outlook" when you make back end maintenance work like moving their mailbox. This is because the mailbox GUID remains the same throughout the life of the mailbox.

7. The protocol head has been moved to the MBX server. Prior to EX2013, the protocol head existed on the CAS and MBX servers for client connections along with the HT server role for transport.

8. The transport service has been split into two services now 1. Transport Submission service 2. Transport Delivery service. Both are mutually exclusive services hence even if the Submission service is mal-functioning, Delivery service will not be impacted.

9. The store process has be re-written in managed code making it more efficient. Also each database gets its own store worker process now which are managed by a host Store process.

10. Exchange 2013 now leverages FAST search technology.

-Ary