We have a subscription licensing model that can be managed from our website. This type of subscription retains intact when you migrate your Access Server data from one machine to another. You can also simply look up this subscription and use the activation key to activate it on your new Access Server. You can activate a subscription multiple times and on multiple Access Server nodes at the same time. They will then simply share the subscription. Each node individually will be able to use all connections on the subscription, but the VPN connections on all Access Servers using the same subscription must not exceed the amount allowed on the subscription. If it does, as many VPN connections are terminated as are necessary to stay with the subscription limit.
We also offer OpenVPN Access Server on Amazon AWS on the AWS Marketplace as tiered instances. These are billed directly through Amazon AWS and you can recognize these on the AWS Marketplace because they have (xx connected devices) in the title of the offering on the AWS Marketplace. If you make an AMI image of such an EC2 instance and then create a new EC2 instance from that image, it will also be licensed. Of course each new instance will increase the amount you are being billed for, so they do not 'share' a single software license. This type of license is tied to the instance metadata which usually does get preserved if you create an AMI image and relaunch from such an AMI image.
We also have the fixed license activation key method. This is recognizable by an activation key that contains 4 groups of 4 characters (LICE-NSEK-EYIN-HERE). If you have such an activation key in use on your OpenVPN Access Server now, please note that this cannot be moved by you to another installation. You will need our help to do so. If you are preparing to reinstall your server or wish to move your Access Server installation to another environment, even virtual, then be prepared that your license will fail to function on the new installation. To resolve this, you can contact us ahead of time and let us know you need your license key reissued for a reinstall. You can do this up to 2 weeks in advance. When we reissue a license key, the old installation will still function for 2 weeks on the old fixed license activation key, while the new one can be activated on the new installation immediately. To get a license key reissued contact us on our OpenVPN Support page. Please note that we can only reissue fixed license activation keys if they are still valid and not expired.