In my very anecdotal experience, the block that most consumer routers ship with as a configured default is, by far, 192.168.1.0/24 or 192.168.0.0/24. I've run a

In my very anecdotal experience, the block that most consumer routers ship with as a configured default is, by far, 192.168.1.0/24 or 192.168.0.0/24. I've run across a handful of 172.*, but they were so exceptional that they stood out. I imagine that vendors (e.g Linksys) are not inclined to change them, perhaps because they simply work for most people, and changing the default would most likely invalidate the rather large number of tutorials, FAQs, guides, etc. that simply assume that IPs are assigned from the 192.168.0.1-254 range.