Our basic plan is, no direct internet connection to a server on the internal network. We use internet facing edge appliances in tier 1 DMZ then content filtering in tier 2, then Exchange on internal network. Reverse proxy in front of OWA (this is E2K3). I expect E2K7 to be similar.
I realize this may not work for everyone but it is our model. --------------------------------- Sent from my BlackBerry Wireless Handheld ----- Original Message ----- From: Peter Johnson <peter.john...@peterstow.com> To: MS-Exchange Admin Issues <exchangelist@lyris.sunbelt-software.com> Sent: Sun Nov 08 11:12:04 2009 Subject: RE: E2k3 Security Question Microsoft's recommendation has always been to put the Front end server/CAS role directly into your network behind the firewall rather than in the DMZ. The reasoning behind this is related to how many holes you have to punch in the internal firewall to allow RPC access from the FE/CAS roles to the DC"s. If you place the FE/CAS servers inside the internal network you only need to open one hole in your internal firewall namely 443. Of course MS recommend putting it behind an ISA server with FBA turned on. I've always run my Exchange Servers this way and have never had a security guy call me on it. Kind Regards Peter Johnson I.T Architect United Kingdom:+44 1285 65842 South Africa: +27 11 252 1100 Swaziland: +268 442 7000 Fax:+27 11 974 7130 Mobile: +2783 306 0019 peter.john...@peterstow.com This email message (including attachments) contains information which may be confidential and/or legally privileged. Unless you are the intended recipient, you may not use, copy or disclose to anyone the message or any information contained in the message or from any attachments that were sent with this email, and If you have received this email message in error, please advise the sender by email, and delete the message. Unauthorised disclosure and/or use of information contained in this email may result in civil and criminal liability. Everything in this e-mail and attachments relating to the official business of Peterstow Aquapower is proprietary to the company. Caution should be observed in placing any reliance upon any information contained in this e-mail, which is not intended to be a representation or inducement to make any decision in relation to Peterstow Aquapower. Any decision taken based on the information provided in this e-mail, should only be made after consultation with appropriate legal, regulatory, tax, technical, business, investment, financial, and accounting advisors. Neither the sender of the e-mail, nor Peterstow Aquapower shall be liable to any party for any direct, indirect or consequential damages, including, without limitation, loss of profit, interruption of business or loss of information, data or software or otherwise. The e-mail address of the sender may not be used, copied, sold, disclosed or incorporated into any database or mailing list for spamming and/or other marketing purposes without the prior consent of Peterstow Aquapower. No warranties are created or implied that an employee of Peterstow Aquapower and/or a contractor of Peterstow Aquapower is authorized to create and send this e-mail. -----Original Message----- From: Kurt Buff [mailto:kurt.b...@gmail.com] Sent: 08 November 2009 19:42 To: MS-Exchange Admin Issues Subject: E2k3 Security Question All, We've got a consultant in-house doing an infrastructure review. One of the things he's recommending for security reasons is that instead of doing SSL direct to our single Exchange servers on our production LANs, we should put front-end servers into our DMZ. I tend to believe that direct SSL (for OWA or RPC/HTTPS) is no less secure than a front-end in a DMZ, but I do confess ignorance, and would like to know more, and have ammunition one way or the other before getting bent out of shape. Where can I find some documents regarding the relative security of these two approaches, and evaluate this for myself before agreeing or disagreeing with him on this? I've been cruising the history of this list, and doing some googling, but can't see a direct discussion of this topic. Thanks, Kurt
