Subject to the "Show us what you tried, so we can help you learn" that the previous posts have tried to express, here are some comments. This sounds a lot like a homework assignment, so you'll have to excuse some skepticism.

take an input of an ip address and ultimately randomize it.

What do you mean by "randomize"? I could guess for a CIDR or a range, but it's not clear what you would do for a single entry.

2. Output will be a list of IPs, one per line sent to STDOUT

And how do you know how many lines? If you are randomizing, as opposed to just outputting all permutations, there is no clear end to the algorithm if you might want more than 1.

3. Output can be redirected to a file or piped to another command “>” or “>>” will redirect to a file.

That's what |, > and >> do to STDOUT on a *NIX command line.

Select a randomization method and create a switch for Linux preferably "-r"

See Getopt::Std or Getopt::Long

5. Use the “-r” switch to randomize the output and redirect to file ie perl script = ip_randomizer -r <IPADDRESS> > <FILENAME>

This is unclear to me, particularly in light of 3 and 4.

If you can clarify, and tell us what you tried and what didn't work, we can be much more helpful.