SBS2008 with all public IP LAN?

Line One
Line One used Ask the Experts™
I would like to install SBS2008 on an existing LAN that is using public IP addresses.  (Public IP addresses are a non-negotiable item in this environment for historic reasons for a particular application.)  It seems that a lot of SBS functionality revolves around the assumption of private IP LAN.  Can I make SBS 2008 function with strictly public IP addresses just as it does with private IP and if so what are the things to do/watch for?
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How are you segregate the external access (internet) from your lan? a IP it´s always a IP. So if you are able to ROUTE the TCP/IP and access Internet from you local network, even using a valid ip, the answer is yes, you can.

Please give us more details about your network structure.


LAN is behind a Cisco PIX506E and is extremely secure (penetration tested).

Most devices on the LAN have static public IP addresses but there is also DHCP from the router.

Note that the LAN side use of public IP addresses cannot be changed for legacy reasons.

The issue here is with SBS2008 configuration:  it expects a single NIC on the server with a non-routable IP address and a non-routable IP address for the LAN side of the router.  My understanding is that if this is not the case, SBS configuration cannot and will not complete.

My thoughts are to complete the configuration in isolation from the existing LAN using a router configured 10.0.etc or 192.168.etc then change the NIC to a public IP address and plug the server back into the network.

Will this work?


I never tested a configuration like that, but I dont see any major technical problem except one point: you MUST use the internet wizard to properly setup your server with the correct IP. if you change this IP, you must rerun the wizard.

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I have a SBS 2k8 for tests purpose. I will simulate that tomorrow and I give you a feed back.


Comments much appreciated, read you loud and clear on using the Internet Wizard.  I'll be testing my idea tomorrow as well starting about 10:00am Pacific.  Only wrinkle may be that my test router will not have an internet connection so I'm hoping that the wizard genie took this into consideration.
Well, it worked.  Hooked up a basic Linksys router and ran the SBS2008 Connect to the Internet wizard and completed the configuration.  Changed the server NIC to a public IP address, plugged it into the network and that was that.  I did have an internet connection though, didn't try it without one.

I try it here and it work fine. Just doing some stress test but until now, everything ok.

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