This really is not a specific question but more of a general thought. I am a newbie when it comes to network right now, just getting through the intro classes. But we are learning CIDR theroy and practice. Of course it is all based on IPv4 The professor talked about how once the switch too IPv6 comes CIDR will be completely different. He did not mention how, which is why I am asking this question. So How soon do you think IPv6 will be common use? And is it worth learning all of this if it is going to be "completely different" EDIT After a bit of my own research I must of heard the professor wrong. As far as I can tell as long as the routing protocol that supports CIDR it should work in ipv6. The question about ipv6 still stands. Should I look into a professor that teached ipv6? Will everything I learn about Ipv4 be useless?