• Status: Solved
  • Priority: Medium
  • Security: Public
  • Views: 369
  • Last Modified:

Migration to Exchange 2013 SP1 - Edge Transport Role

We're planning on moving to Exchange 2013 SP1. From all the information I could find, it seems that the Edge Transport role is to be placed in the perimeter network for incoming SMTP traffic. My question is, let's say the CAS role (along with the Mailbox Server role) resides on our internal network - do Outlook 2010/2013 users that connect to our organization from the outside do so through the Edge Transport server, or would they connect directly to our internal corporate LAN where the CAS is hosted?

And if they connect directly to out internal corporate LAN where our CAS is hosted, is there a way to force that traffic instead to go through the Edge Tranport server first, or would the CAS role also have to be installed on our perimeter network for this to work?

Basically, we would prefer that any traffic coming through the outside goes through our DMZ first. We would like to avoid having to open any port to our corporate LAN. I really appreciate any insight someone could offer into this. Thanks.

- Dave
1 Solution
IvanSystem EngineerCommented:

as I know Edge is only there for SMTP flow, meaning that only email coming or going to your organization will go thru it.
Client connections for Outlook Anywhere, POP3, IMAP will go directly to CAS, so you would have to open SSL and any other required port.

Edge is not a part of AD domain, so it cannot authenticate clients. Clients are authenticated and then proxy from CAS to Mailbox.

glass81Author Commented:
So there's no way to accept connections for CAS from the edge transport server - kind of like routing all requests through there first? Maybe I'm off base here, but it sounds convenient to have port 443 open on the edge transport server as opposed to opening it directly on your internal corporate LAN.
Simon Butler (Sembee)ConsultantCommented:
Edge is a waste of money in my opinion, for exactly the reasons you have identified - it only does SMTP traffic. It has nothing to do with any other role. Therefore I never deploy one. I can achieve 90% of the functionality of Edge with third party products, and usually get more functionality that Edge cannot provide from those same products.

Most deployments I do will bring port 443 straight in to Exchange. Putting it through a DMZ does nothing for security. If you have a 1990s security policy that states nothing internal should be exposed to the internet, then use a separate server to do ARR.

The Exchange product team has outlined how to do that for Exchange 2013 here:

Also, I wouldn't be deploying Exchange 2013 SP1. That is very old now (effectively CU 4). New deployments should go straight to CU7. The cumulative updates are the complete product, so just download it from the public site, extract and install.

Free tool for managing users' photos in Office 365

Easily upload multiple users’ photos to Office 365. Manage them with an intuitive GUI and use handy built-in cropping and resizing options. Link photos with users based on Azure AD attributes. Free tool!

Gareth GudgerCommented:
I agree with Simon. And if I could give him a +1 I would. ;)

There are a number of reverse proxies on the market. Many doing double duty as load balancers as well. ARR is a great free alternative from Microsoft. But it requires a server in the DMZ with IIS installed.
glass81Author Commented:
Unfortunately Simon, we kind of do have that type of network. I understand that if our server hosting ARR is compromised in the DMZ, it would be just as bad as having our CAS compromised on our internal network.

I can't convince the IT Director otherwise, but I do appreciate the clarification, and ultimately, your help on this topic.
Gareth GudgerCommented:
If they don't want to go with ARR, then you could look at a reverse proxy / load balancer like a KEMP.

They offer them as hardware or virtual models.
Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.

Join & Write a Comment

Featured Post

Easily manage email signatures in Office 365

Managing email signatures in Office 365 can be a challenging task if you don't have the right tool. CodeTwo Email Signatures for Office 365 will help you implement a unified email signature look, no matter what email client is used by users. Test it for free!

Tackle projects and never again get stuck behind a technical roadblock.
Join Now