Nortel Aquried the 47.x.x.x. class A network from Bell Northern Research when they took them over in the late 90's so chances these are from this block

As far as I recall from when I worked in Nortels R&D Organisation Nortel had the whole of the 16.x.x.x A class network so I bet this 600 thousand or so are from that block

My first foray into linux was the MCC interim release on October 1992 whilst at Manchester University. I installed it on a 40Meg Partition on my 386DX25 and the reason was to allow me to do the programming course works without been tied to going into the Unix computer lab. I still remember using 0.95 of the linux kernel and remember the excitement on the course when 1.0 of the linux kernel was released. Ah them were the days. Memories..............