How to sort IP addresses

How to sort IP addresses

>cat sortme.txt
192.168.0.5
192.168.0.3
192.168.0.2
192.168.0.1
192.168.0.3
..

>sort -n -t . -k 1,1 -k 2,2 -k 3,3 -k4,4 sortme.txt
192.168.0.1
192.168.0.2
192.168.0.3
192.168.0.3
192.168.0.5

OR to sort and remove duplicates:

>sort -n -t . -k 1,1 -k 2,2 -k 3,3 -k4,4 sortme.txt | uniq

192.168.0.1
192.168.0.2
192.168.0.3
192.168.0.5