If no individual element of the 'numbers' is > 255

$/ = "\n";;
print for map{ 
    join '.', unpack 'C*', $_ 
} sort map{ 
    pack 'C*', split '\.'
} qw[1.1 11.2.3 2.3 11.2.1];;

1.1
2.3
11.2.1
11.2.3
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Update: In fact, utilising Unicode, this can handle individual number elements upto >64,000. Which ought to be enough as it would allow a 3-part version number to handle 1 new version every microsecond for a project life exceeding 8 years before it encountered problems.

print for map{ 
    join'.',unpack'U*',$_ 
} sort map{ 
    pack'U*',split '\.', "1.2.$_.4" 
} reverse qw[ 1 11 111 127 127 128 129 254 255 256 257 1111 11111 6400
+0 ];;
1.2.1.4
1.2.11.4
1.2.111.4
1.2.127.4
1.2.127.4
1.2.128.4
1.2.129.4
1.2.254.4
1.2.255.4
1.2.256.4
1.2.257.4
1.2.1111.4
1.2.11111.4
1.2.64000.4
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