I have my exchange server routing mail through my ISA 2006 server just fine. Now i have a second smtp server which is a Strongmail solution. I need to route these emails to the internet and thats working just fine as well. I need the Strongmail email to exit the ISA with a secondary IP address and currently they show the defualt external IP address. Please share any ideas you have for me.
This Question has been solved and asker verified All Experts Exchange premium technology solutions are available to subscription members.
Experts Exchange has been collecting answers to technology questions since 1996…3 million and counting! If you have a question, chances are we already have your answer.
If you can't find the exact answer you're looking for, ask our exclusive community of 50,000 experts. You’ll get a personalized answer from a trusted professional.
Thousands of free tech tips, tricks, how-to’s and tutorials are available in our peer reviewed articles section. See for yourself how smart our experts are, no login required.
Save solutions to your questions, answers you’ve discovered through searching plus helpful articles in your personal knowledgebase for easy future access.
Access the answers to your technology questions today.
30-day free trial. Register in 60 seconds.
Members of the expert community talk about why the experience at Experts Exchange is different than what you will find anywhere else.
Try it out and discover for yourself.
30-day free trial. Register in 60 seconds.
Join the community of experts here and help other tech pros by answering question in your area of expertise. You can earn FREE access to all Experts Exchange's premium features and resources.
The repercussions depend on what else you have in the environment.
For example, the NAT function is what 'hides' the internal ip addresses by replacing this with the ISA external IP address as the source address. If you route, then the originating source IP address is kept in the packet. However, if you have another device between the ISA and the internet such as another firewall or router, then THAT can perform the NAT for you instead assuming it can perform 1-to-1 NAT functions (it is this function that ISA does not support).
If you do not have another device that can perform the NAT then you have a problem. Assuming you have used a private subnet internally such as 192.168.1.0, for example, then these addresses would be sent over the internet if natting was not in place. As this subnet is not routeable, it will all end in tears. In this scenario, you would HAVE to NAT the relationship but it defeats your core objective of course.
Business Accounts
Answer for Membership
by: keith_alabasterPosted on 2009-10-21 at 22:52:07ID: 25631143
Never going to happen with ISA Server - it is not supported in a NAT configuration and operates - by design - in the way you have noticed for outbound traffic. Because the traffic is NAT'ed, ISA will always use its main external IP address as the source ip for outbound traffic. Obviously, response traffic from inbound packets goes back out with the same address as the one it arrived with.
Only way this could be done would be to change the NAT relationship between the internal and external nics (ISA gui - configuration - networks - network rules) to a route relationship whilst using public IP addresses on the ISA external nic.