In an example embodiment, there is described herein a technique that provides network availability to wireless clients (e.g. wireless clients running mission critical applications such as voice applications or medical devices) when a portions of a network is unavailable, such as when performing an image upgrade. One or more access points are switched to a standalone mode of operation, for example an AP that can operate using HREAP (Hybrid Remote Edge Access Point) mode, for maintaining network availability while a portion of the network is unavailable.