The upgrade path for VIP Enterprise Gateway is one version at a time (e.g., 9.1 to 9.2 to 9.3 to 9.4, etc). Alternatively, a new installation of the current version may be deployed.
In VIP EG 9.5 a LiveUpdate feature was introduced to automate upgrades. Upgrades can be applied from the VIP Enterprise Gateway console by going to Settings > Update Settings and selecting the option to check for updates manually.
Starting with VIP EG 9.8, settings can be exported from an existing VIP EG server of version 9.1 or newer directly into a new 9.8 server without incremental updates.