Moved kit
We had something like this happen at an organisation (UK gov) where I worked on their service desk. Saturday morning on call and started getting calls that no one could get onto the network via vpn. After a few enquiries it was found that a project team were moving the 3G concentrator from a location near Heathrow to HQ in Central London. 2 identical boxes! Yep they had disconnected the VPN concentrator! It was rushed back to Heathrow in a hurry before they closed up access to the location and I believe some labelling was applied