Exchange Server 2003 Dynamic IP

[Zach]

TSCustomer

I have an issue which I would need your invaluable assistance. I am planning to deploy a MS EXCHANGE 2003 messaging environment for my clients, and the ISP that supplies their Internet access uses a dynamic IP address. Would that work for the deployment considering the fact that OWA would be enabled as well? Am sort of confused; kindly help with your expertise.

[DShack]

The best resolution is to see if they can change to an ISP who can provide a static IP address. That will put them in a solid position to support inbound mail.

If they absolutely cannot obtain a static IP address, then there are some options available.

- Because your server will have short outages now and then due to IP changes, you will want to use an external hosted anti-spam and relay service that vendors like MXLogic, ZoneEdit and many others can offer. They will be the primary endpoint for your email and then they will forward mail on to whichever FQDN you configure. So you could have them deliver your mail to mail.slippery.org, and mail.slippery.org could be a host with a dynamic IP address and a dynamic DNS record.

- Use a dynamic DNS record. Ok, so how do you set up mail.slippery.org? Go to No-IP.com or DynDns.org and sign up for a free generic dynamic DNS name. Or pay a yearly fee and use your own domain name there. You would install a small client app on your server which would make sure that the dynamic DNS vendor always has your current IP. So mail.slippery.org would always map to your current dynamic IP and your mail delivery host could reliably deliver mail to your server.

Problems: when you use something like MXLogic or another smart host, you typically need to specify which IP address you are going to send from, so if you have a dynamic IP, you may need to define a somewhat large subnet to cover the possible addresses that your server may be sending from. A better idea to handle outbound is to have your server use your ISP's smarthost to deliver outbound mail. That would be the least hassle.

Another issue you will run into if you DON'T use a smart host is that because your IP is in a dynamic pool, most big ISP's have already blacklisted mail originating from your server's IP. Because of that, it's critically important that you be using a smarthost, probably your ISP's.

As long as you are taking care of the DNS side of things properly with something like DynDns, you shouldn't have any issues with OWA. If you can ping your external name, whether that's itchyfeetball.myip.com or mail.slippery.org, you should be able to use OWA if you've configured your server properly. The fact that you are using a dynamic IP will not affect your server-side setup of OWA at all.

Hope that helps,

Dave Shackelford