Linux: how to get the difference between two lists?

Question

linux

There are two files with lists of hosts (IP Addr key field). How can you get the difference difference between these lists without using databases or programming languages ​​(ie purely BASH)?
Using join and paste has not succeeded so far.

Answer 1

diff -y ./ip.dat ./ip2.dat --suppress-common-lines
or simply
diff ./ip.dat ./ip2.dat --suppress-common-lines

Answer 2

First sort (if they are unordered) is the sort command, then difference is the diff command.

Answer 3

sort, diff, uniq, awk - depending on what kind of files and in what form the data is.

Answer 4

There is another com

Answer 5

diff+grep+wc