UNIX for Dummies Questions & Answers

Hello. First time poster here. I have a huge file of IP numbers. I am trying to output only the class b of the IPs and rank them by most common and output the total # of duplicate class b's before the class b. An example is below:
12.107.1.1
12.107.9.54
12.108.3.89
12.109.109.4
12.109.6.3


Output would be:
2 12.107
2 12.109

Thanks for the help
Crunchtime

As you can see, a simple script does the trick

[dummy806]@@ecar0o:/opt/oracle/TOOLS/generic_unix/scripts> cat ttt
12.107.1.1
12.107.9.54
12.108.3.89
12.109.109.4
12.109.6.3
[dummy806]@@ecar0o:/opt/oracle/TOOLS/generic_unix/scripts> for i in `cat ttt | cut -d"." -f1,2 | uniq`
more>do
more> num=`cat ttt | grep $i | wc -l`
more> if (( $num > 1 ))
more> then
more> echo $num $i
more> fi
more>done
2 12.107
2 12.109

THanks so much man!