Problem:   How can I sort a file of IP addresses?

Answer:    You have to tell sort to sort them numerically by field.

This doesn't work:
	sort -n -t. file_with_ip_addrs
	
10.1.1.1
10.1.1.11
10.1.1.112
10.1.1.12
10.1.1.2
10.1.1.20
10.1.1.21


Try this instead
	sort -n -t. -k 1,1 -k 2,2 -k 3,3 -k 4,4 file_with_ip_addrs
	
10.1.1.1
10.1.1.2
10.1.1.11
10.1.1.12
10.1.1.20
10.1.1.21
10.1.1.112






-Contributed by:  Arshad Khan