An RT-AC66U I purchased today lists its firmware version as 188.8.131.52.202. Yes I mean 202. This firmware is listed at RT-AC66R Downloads as the initial firmware for the RT-AC66R, followed by 184.108.40.206.246 and 220.127.116.11.260. Despite coming with RT-AC66R firmware, the router box and the router itself claim it is an RT-AC66U and it was not bought at a Best Buy (where RT-AC66Us are reportedly sold as RT-AC66Rs). The Authentication Method list that my router shows me under Wireless | General looks like that described for the RT-AC66R at the Asus web site when comparing the RT-AC66U to the RPT-AC66R. It includes Radius with 802.1x, for example. I don't know what to make of it. The discussion in Asus RT-AC66R vs. RT-AC66U doesn't help. Edit: I had initially searched for 18.104.22.168.202 and found little. Once I searched this forum for RT-AC66R I found a number of posts that explain this somewhat.