You may recall the problems I had downloading the Fedora Core 3 ISO image a while back. Well, I did finally get a good copy downloaded and installed. I did a bit of analysis on the downloaded images, and determined that there had been a couple of four-byte changes. This was something of a mystery, but nothing notable.
I was mentioning this to Rohan just now, and he twigged on the “four bytes” part of this. In particular, he wanted to know what the bytes had been changed from and to.
In the non-corrupt image, there is a byte pattern of “D1 1E 21 0D” starting at (decimal) position 634,912,768 and at decimal position 11,875,12,320.
In my first download (which was paused and resumed over several days), that set of bytes at 11,875,12,320 was inexplicably “C0 A8 00 6C.”
In my second download, both sets were “C0 A8 00 6C.”
In the third download (several days later), the image was uncorrupted.
Rohan’s specific question was: “So, do those look like reasonable IP addresses?”
Let’s see… C0 A8 00 6C… 192.168.0.108.
Oh. My. God.
Let’s check something about the bytes that it replaced… they’re 126.96.36.199.
SBC Internet Services - Southwest SBCIS-SBIS-20930 (NET-209-30-0-0-1) 188.8.131.52 - 184.108.40.206 PPPoX Pool bras2.rcsntx SBC209030032000031209 (NET-209-30-32-0-1) 220.127.116.11 - 18.104.22.168
Yep. That’s my ISP.
My NAT saw its external IP address in the incoming data, and decided to change it to the internal IP address of my machine to “fix” things.
I’m using a different NAT now.