Sort by field

/tmp/input:

192.168.1.100
192.168.1.19
192.168.1.102
192.168.2.1
192.168.0.2

# sort -t . -k 3,3n -k 4,4n /tmp/input

-t . : Set field to . (dot) as our IPs separated by dot symbol
-n : Makes the program sort according to numerical value
-k opts: Sort data / fields using the given column number. For example, the option -k 2 made the program sort using the second column of data. The option -k 3,3n -k 4,4n sorts each column. First it will sort 3rd column and then 4th column.

Output:

192.168.0.2
192.168.1.19
192.168.1.100
192.168.1.102
192.168.2.1

Referência