An alternate solution:

(1)-build hash of the data
(2)-delete the keys that are not needed
(3)-print what is "left over"

below I left 10.2.9.3 out of the "exclusion data" to show what would happen.

#!/usr/bin/perl -w
use strict;

my $tmpdata=<<END;
Source           Destination    Packets         Bytes
 15.254.32.120    10.2.9.2        5              504
 209.68.19.130    10.2.9.4       33            15941
 17.149.36.162    10.2.9.3       14             3416
 17.149.36.15     10.2.9.3       14             3404
 67.148.147.65    10.2.9.5       57            39207
 8.8.8.8          10.2.9.6       84             8006

Accounting data age is 0w1d
Box#
END

my %destination; #a hash of array

#
# read in all the data
#
open my $TMPDATA, '<', \$tmpdata or die "cannot open tmpdata $!";
while (<$TMPDATA>) 
{
   my ($ipSource, $ipDestination, $packets, $bytes) =
         /^\s*([\d.]+)\s+([\d.]+)\s+(\d+)\s+(\d+)\s*$/;
   next unless defined $bytes;
   
   push @{$destination{$ipDestination}}, [$ipSource,$packets, $bytes];
}
close $TMPDATA;

#
# exclude (delete) some data
#

while (<DATA>)
{
   next if /^\s*$/;  #skip blanks
   chomp;

   delete $destination{$_} if exists $destination{$_};
}

#
# print what is left over
#

foreach my $dest ( sort keys %destination)
{
   foreach my $source_ref (@{$destination{$dest}})
   {
      printf "%s\t$dest\t%s\t%s\n", @$source_ref;
   }
}

=prints
17.149.36.162   10.2.9.3    14  3416
17.149.36.15    10.2.9.3    14  3404
209.68.19.130   10.2.9.4    33  15941
67.148.147.65   10.2.9.5    57  39207
=cut

__DATA__
10.2.9.2
10.2.9.6
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