use strict;
my @ips = (
		"1.2.3.4",
		"1.2.3.5",
		"1.2.3.3",
		"2.2.3.4",
		"1.0.2.3");

@ips = map {$_->[1]} 
		sort {$a->[0] cmp $b->[0]} 
			map {	[
						join(".", 
								map {sprintf "%03d", $_} 
									split('\.', $_)
						),
						$_
					]
			} @ips;					
print join "\n", @ips;

__OUTPUT__
1.0.2.3
1.2.3.3
1.2.3.4
1.2.3.5
2.2.3.4