Really? I don't get any failures:

#!/usr/bin/perl

use strict;
use warnings;

my $re_ip = qr/(\d+\.\d+\.\d+\.\d+):\d+/;
my $re_line = qr/ ^ \s* $re_ip \s* -> \s* $re_ip \s* -> \s* $re_ip /x;

my $line_count = my $match_count = 0;
while (<DATA>) {
    $line_count ++;
    $match_count ++ if /$re_line/
}

my $failures = $line_count - $match_count;
print "There were $failures failures\n";

__DATA__
136.1.1.154:33672 ->  64.210.209.51:80 ->  192.168.1.145:80           
+ tcp
65.201.211.176:14664 ->  64.210.209.54:80 ->   192.168.1.78:80        
+    tcp
    67.38.95.86:2116 ->  64.210.209.50:80 ->  192.168.1.103:80        
+    tcp
198.49.222.246:52469 ->  64.210.209.54:80 ->   192.168.1.79:80        
+    tcp
193.80.106.152:3781 ->  64.210.209.61:80 ->   192.168.1.81:80         
+   tcp
    67.28.79.24:3248 ->  64.210.209.54:80 ->   192.168.1.79:80        
+    tcp
128.187.192.39:1218 ->  64.210.209.54:80 ->   192.168.1.78:80         
+   tcp
128.187.192.39:1209 ->  64.210.209.51:80 ->  192.168.1.144:80

There were 0 failures
[download]

And I copied and pasted both your examples and your regexes.

Abigail