As of today I've currently taken and passed 3 computer networking classes at the undergraduate level and one at the graduate level and never have I seen or heard mention of CIDR.  I've learned about how to specify blocks of IP's but they are always Class A, B or C blocks.  I'm sorely dissapointed that none of these classes is teaching CIDR instead of the old way of allocating addresses.  I mean, really, is it that hard to update the curriculum...its not like CIDR is a very recent development...more on CIDR .  Oh well, I guess this just backs up the argument that in the world of IT formal education is not as important as real world experience.