my ($cap, %dest);

# Open a file and slurp in the entire contents to one scalar
open(CAP, "$file");
    while(<CAP>) { $cap .= $_; }
close CAP;

# Scan through the contents for source/dest pairs and keep track of how many times the dest gets hit:
while($cap =~ /\s+(?:(?:\d{1,3}\.){3}\d{1,3})\s+->(\d{1,3}\.){3}\d{1,3})\s+/g) {
    unless(exists($dest{$1})) { $dest{$1} = 1; }
    else { $dest{$1}++; }
}

# Print out the destinations and the number of times they were hit in descending order
foreach my $dest_addr (sort { $dest{$b} <=> $dest{$a} } keys %dest) 
    { print "$dest_addr\t$dest{$dest_addr}\n"; }