Fascinating stuff. I've spent half of this year picking up the rudiments of network engineering, and it's absolutely fascinating to me that IPv6 attempts to return to the "end to end" principle we lost with IPv4 NAT. (Peering disputes around IPv6 are only tangentially related to this, of course, but two neurons grazed past each other when I read this.) Of note (for me) are the other links on this post -- the "looking glass" sites for those providers are new to me! Also, the "cheap VPS" and "subnetting cheatsheets" seem handy.