Not sure where your router is getting that remote name; it isn't the reverse name on that IP address. As dsilvers
states, '1e100.net' is a Google domain. As an aside, it has to do with the fact that 1.0x10¹°° can be written as 1e100; the mathematicians call this a, "Googol"
The other puzzle is the 18.104.22.168 reported as a local IP address. Seeing the actual, unedited log entry might be revealing.--
~Oh Lord, why have you come
~To Konnyu, with the Lion and the Drum