Personally, I'd refrain from using one regex for all your querying -- I find it to hard to read.

Why not just use split() and then use regexes on the individual fields? A sample loop for processing line by line:

$user_param{source_addr} ||= '.'; # default value for param
$user_param{dest_addr} ||= '.';

while (<DATA>) {
    my @data = split(/\s/, $_);
    next unless $data[2] =~ $user_param{source_addr};        
    next unless $data[3] =~ $user_param{dest_addr};
    # ...

    print $_;
}
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