1/8 was reserved for a long time and various entities improperly used it as a private address. It was eventually given to APNIC for assignment use but a few ult

1/8 was reserved for a long time and various entities improperly used it as a private address. It was eventually given to APNIC for assignment use but a few ultra-commonly-used ranges and addresses like 1.1.1/24 and 1.2.3/something were never assigned because they get so much noise traffic and would break so many things. It's improper for anything to use these unassigned in-theory-globally-routable addresses but there are no real hosts there and lots of local networks use them for random internal purposes. At least one commercial Wi-Fi hotspot uses 1.1.1.1 as a captive portal address. Here's an incredibly detailed report on the situation on the 1-network: http://www.potaroo.net/studies/1slash8/1slash8.html http://www.potaroo.net/studies/1slash8/1slash8.html