That server would provide an open path to the LAT through the VPN connection. All deployment is based on risk assessment. Only you can determine if the dangers of a given setup are outweighed by the benefits. Generally, only those protocols that need to pass between DMZ and LAT should be allowed. Allowing AD traffic to the DMZ is dangerous, regardless of how you allow it. Jim Harrison MCP(2K), A+, Network+, PCG ----- Original Message ----- From: "Jay" <jschwarzkopf@xxxxxxxxxx> To: "[ISAserver.org Discussion List]" <isalist@xxxxxxxxxxxxx> Sent: Friday, August 10, 2001 7:49 AM Subject: [isalist] Re: DNS Subnet question with DMZ http://www.ISAserver.org Okay. What about server in perimeter network of back-to-back (using different firewalls), with VPN connection into internal ISA firewall? Is that anymore a security concern than published ports? ----- Original Message ----- From: Jim Harrison To: [ISAserver.org Discussion List] Sent: Friday, August 10, 2001 10:27 AM Subject: [isalist] Re: DNS Subnet question with DMZ http://www.ISAserver.org A DMZ provides isolation of your trusted network from your "publicly-available" servers" Some like to think of the DMZ as the "sacrificial lamb", and to a degree it is. The general idea is that if someone wants to trash something, let it be in the DMZ. By the same token, if someone were to trash your DMZ server, they still don't have direct access to the trusted LAN. Jim Harrison MCP(2K), A+, Network+, PCG ----- Original Message ----- From: Jay To: [ISAserver.org Discussion List] Sent: Friday, August 10, 2001 7:18 AM Subject: [isalist] Re: DNS Subnet question with DMZ http://www.ISAserver.org Is there a benefit of putting E2k (or any server) on DMZ, over just publishing it from internal net? ----- Original Message ----- From: Jim Harrison To: [ISAserver.org Discussion List] Sent: Friday, August 10, 2001 9:38 AM Subject: [isalist] Re: DNS Subnet question with DMZ http://www.ISAserver.org Unfortunately, the best you can do for the DMZ server is a single IP with the set you're given. Since the DMZ in a three--homed ISA is a subnet of the external subnet, you have to use a /30 mask for the DMZ, giving you only 2 usable IPs; one for the ISA DMZ NIC and one left for a server. Is the Exchange server an E2K variation? If so, placing it in the DMZ is more trouble than it's worth, given the issues related to AD membership across a firewall. Jim Harrison MCP(2K), A+, Network+, PCG ----- Original Message ----- From: cismic To: [ISAserver.org Discussion List] Sent: Thursday, August 09, 2001 9:51 PM Subject: [isalist] DNS Subnet question with DMZ http://www.ISAserver.org I also posted this to the message boards. Sorry for the duplication. Just thought I'd see if anyone was online tonight with some ideas. J Hello, I'm using 10.0.0.1 for illustration: I have 10.0.0.1/29 (8 IPs, 32 per C) as my ip address. IP'S .1 and .8 are being used by my ISP. .7 is assigned to my CISCO 776M ISDN router. That leaves me with 5 ip address to use. .2, .3, .4, .5, .6 EXT NIC 1. = .2 DMZ NIC 1. = .3 DMZ servers would be .4, .5, .6 If I split those into something like the following .4 sql .5 web .6 DNS I run out of address and won't be able to place my exchange server in the dmz. and Internal NIC private could be 10.0.1.0 Is there another method that will work just as well so I can publish my Exchange server? ------------------------------------------------------ You are currently subscribed to this ISAserver.org Discussion List as: jim@xxxxxxxxxxxx To unsubscribe send a blank email to $subst('Email.Unsub') ------------------------------------------------------ You are currently subscribed to this ISAserver.org Discussion List as: jschwarzkopf@xxxxxxxxxx To unsubscribe send a blank email to $subst('Email.Unsub') ------------------------------------------------------ You are currently subscribed to this ISAserver.org Discussion List as: jim@xxxxxxxxxxxx To unsubscribe send a blank email to $subst('Email.Unsub') ------------------------------------------------------ You are currently subscribed to this ISAserver.org Discussion List as: jschwarzkopf@xxxxxxxxxx To unsubscribe send a blank email to $subst('Email.Unsub') ------------------------------------------------------ You are currently subscribed to this ISAserver.org Discussion List as: jim@xxxxxxxxxxxx To unsubscribe send a blank email to $subst('Email.Unsub')