open my $tailf, "tail -f $logFile |" or die;
while (<$tailf>) {
    chomp;
    my $line = $_;
    if($line =~ m/ on $ipaddress/)
    {
        if (scalar(@matches) <= 2){
            push(@matches, $line);
        }        
        else {
            last;
        }
    }
}

foreach $line (@matches){
     print "$line\n";
}
		
close $tailf;