... is not currently possible

Use cases

Suppose that you have done one of the following on / for a NeCTAR virtual:

  • You have obtained a license key for some proprietary software that requires you to use a specific MAC address or IP address to run the software.
  • You have implemented a service that lots of people use, and provided them with the IP address so that they can connect.
  • You have obtained a proper (not self-signed) SSL certificate for the IP address.
  • You have requested the creation of a DNS alias in some external domain (e.g. in your home University) that points to the NeCTAR virtual's IP address (or more likely ... to the corresponding synthetic DNS name).

Now suppose that for some reason you need to reprovision your virtual.  For example:

  • You may need to resize it; i.e. change its 'flavor'.  (In theory, that should be possible to resize a virtual without terminating it, but the reality is that this is currently not supported; see Resizing a NeCTAR Virtual.)
  • You may need to move it to a different availability zone.
  • You may need to rebuild the virtual on top of a different (e.g. newer) Image.  (OK, there are other ways to do this, but ...)

All of these mean that it is highly inconvenient (and in extreme cases impossible) to run your service on a virtual with a different MAC and/or IP address.

The Problem

When you terminate a NeCTAR virtual and create a new one to replace it, the new virtual will have a different MAC address and IP address.  Furthermore, the NeCTAR Dashboard provides no way to specify a MAC or IP address when you create an instance, or change either of these after the fact.  As far as I know, none of the "client" tools do either.

The Workarounds

The only way around this problem is to come up with a strategy that avoids having to terminate your existing NeCTAR virtual.

  • Resizing the existing virtual might be possible (after all): ask NeCTAR support.  (It has to be done manually, and is only possible at some Nodes, and under some conditions.)
  • If you don't need to resize or change availability zones, then you could potentially reimage your virtual; see Reimaging a NeCTAR Virtual.