I have a 60Ghz link to a mountain mast, yesterday it simply stopped working, I had no communication with it and it was not showing in Winbox search, it has by default 192.168.88.200 on AP and 192.168.88.100 on the station, so I set 192.168.88.99/24 gateway 192.168.88.1 on my network PC network card, still nothing unable to get too them, the AP is 40 ft up and needs a Cherry Picker for access, the station is up a mountain, so in desperation I tried disconnecting from the network and connecting the PC direct in to the POE, low and behold the AP was visible and I could get on it, so started checking it out but could not spot anything out of the ordinary and the two radios had a connection but no data was passing between them, being a main link and 60 Customers off the link, i had to do something fast, so I restored the AP backup and low and behold the link was restored and data was now passing between the units, I then connected them to a different network to check the DHCP clients were working and the were, so connected back to main Network and everything was back working, twice it has done it, next time I will backup the radio and download the support files before I restore my backup.