5 things to consider when changing the IP of an Exchange server

We are all faced, from time to time, with the need to change the IP address of our Microsoft Exchange server.
There is no hard relation between the operation of your Exchange server and its IP address thus changing the latter will not break your system.

In short this operation can be considered as safe however it requires a certain level of planning and considerations. I will try to cover in this article the various things you should think about before and after actually changing the IP of your server.

1. Internal DNS
After the IP address is changed make sure that the new IP is registered in the DNS and that the old IP is removed.
Also keep in mind that, if you have a large organization, DNS changes will take sometime to replicate all over and this might temporarily affect your email flow.

2. External DNS
If this IP change will be followed by a change of the public IP of your exchange server you will need to

  • Change your MX record to reflect the new public IP address
  • Change any SPF record you have to the new IP address
  • Create the corresponding PTR record for your new IP and make sure it reflects your mail server FQDN

3. External/Perimeter Network

Depending on the role assumed by the affected exchange server and the configuration of your network you might need to

  • Change any port forwarding rule to point to the new IP address
  • If you use a mail filter change the IP this filter relays inbound emails to
  • If your email server uses a relay host make sure to allow relaying to the new Exchange IP address

4. Internal Network

  • If you have any application(s) that is configured to use your exchange server to send email based on its IP address these should be also revisited and changed accordingly.
  • If you are changing to a completely different and new subnet range make sure to update Active Directory Sites to reflect these changes

5. Exchange Server

Finally on the Exchange server itself  double check if you have any connector &/or websites bound to a specific IP address instead of all IPs

In summary, when planned correctly, changing the IP address of an Exchange server is a smooth and risk free operation.

Did I miss something ? Share it with us in the comments

I have been working in IT consultancy and solution integration since 1998 and I consider myself lucky to be, one in a few, making a living out of my passion. I am also member of the famous Experts Exchange (profile here) online community where I try my best to share what I have learned along the road.

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2 comments on “5 things to consider when changing the IP of an Exchange server
  1. Luciano Saul Cardozo says:

    Hi! I change my external public IP (other service provider), and now, my echange does no send emails. The receiveing is OK. Any tips? Cheers!

    • Jeroen Leeflang says:

      Do you use a specific service provider smtp server as a smarthost? These normally only accept email comming from an ip adress provided by the service provider itself.

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