Windows Azure and Fixed IP Addresses


Several folk that I work with have asked about the ability to reserve a fixed IP address for their Windows Azure services.

This is often needed in order to provide access on a whitelisting service, proxy or firewall.
Windows Azure does not offer this functionality. A virtual IP address is determined for you at deployment time and will remain fixed from that point on until the deployment is actually deleted. For further details see this blog post by Corey Sanders.

But what about when I delete my deployment to upgrade my service?
In the past a change to the Service Definition (increasing or decreasing the size of a VM, Changing role endpoints, Adding or removing roles etc.) would require a full re-deployment. Because IP Addresses are allocated at deployment time, deleting the deployment would reallocate your previous address to the pool and the re-deployment would likely result in a new IP Address.

As of Oct 2011 this is no longer the case!

Most of these updates can now be performed on a running deployment, without having to delete and redeploy.
See this blog post by Drew McDaniel for more details.
The MSDN documentation has been updated to reflect these changes.

Note: These update types are only available with SDK v1.5 and beyond.

So… whilst we don’t give you the ability to reserve an IP address, with the new in-place and VIP-swap update capabilities, nearly every software update scenario may be performed without a delete+redeploy, resulting in a stable IP address for the vast majority of applications in Windows Azure.

Comments (6)

  1. Mario Medina says:

    This is a problem. Some services, like replicating database, require that the hosts have static, immutable IP address. I just upgraded two servers, and after that I got two new IP addresses, and I was forced to reconfigure all the replication parameters, a task that could be saved if you fix this problem.

  2. Mike says:

    All of my applications are .Net/SQL server based and it's sad that I'm forced to host my apps with AWS.  

  3. Eric says:

    So we do an in-place upgrade without a VIP swap, and when for some reason the upgrade fails, how do we roll back without the VIP swap?

  4. Oliver says:

    This is definitely a missing feautre. In case anything goes wrong you might be forced to delete your deployment. Or what is you simply want to change the name of your cloud service?

    There should be an option to "buy an IP address" for a monthly fee, then being able to use this ip address for the cloud service instead of taking one from the pool.

  5. Akash Kava says:

    You are just creating good news article, however after realizing potential bottleneck of static IPs, you are training users to learn about cloud computing and go to your competitor who provides static IPs.

    First of all, everything you said is fine, but I still don't trust your infrastructure 100%, what if we don't do anything that will cause release of IP but if any of your services crashes or go down and when you start them up from your infrastructure that reallocates IPs, we can't live with it.

    And here is another problem with CNAME.

    Second, you are wasting DNS resources,as 15 seconds TTL slows down our sites regardless of what you do. For a good performance DNS TTL needs to be atleast couple of hours, because no user will finish its job in 15 seconds. This means that in reality, every request by user will eventually make new DNS request.

  6. Antonio says:

    No more grief 🙂

    5 free static IP per subscription…/dn690120.aspx