use strict;
open(NB, "nbt.csv") or die "Error reading nbt.csv: $!\n";

while(<NB>){
   chomp;
   @nbtstat = `nbtstat -a $_`;
   %_=map{$_,1}map{/^\d+.\d+\.\d+\.\d+/;$&}($_,@nbtstat);
   print join(',',$_,keys(%_)),"\n";
}