Host checking with fping stalling

[routenull0]

Running v1.23 with fping: Version 3.13

This does not happen using standard ping either, which is just like issue #485 mentions. I notice fping sweeping the entire subnet instead of just the active hosts.

Following subnets setup for Host(Ping Check):
192.168.25.0/24
172.17.0.0/16

pingCheck.php seems to stall. If I manually run the script, it loads up and pings through 192.168.25.0/24 and returns results to the command line but stalls indefinitely at:

192.168.25.254 : xmt/rcv/%loss = 1/0/100%

Until I try to ctrl-c the script, then it runs through the 172.17.0.0/16 subnet, to eventually stall on at:

172.17.255.254 : xmt/rcv/%loss = 0/0/0%

The oddity is there are no assigned IP's in 172.17.0.0/16 to ping check. I can disable host checking on the 172.17.0.0/16 and the pingCheck.php scripts completes without issue and updates the assigned IP's in the 192.168.25.0/24 just fine. Disabling host checking on the 192.168.25.0/24 and enabling it on the 172.17.0.0/16 and running pingCheck.php comes back with "No addresses to check", which is still true since nothing has been assigned in that subnet. But why when both 192.168.25.0/24 and 172.17.0.0/16 are enabled for host checking does it attempt to ping through 172.17.0.0/16 when no hosts are assigned?

[routenull0]

It looks like pingCheck.php sets fping to ping the subnet, unless I am reading the code below wrong:

for ($i = 0; $i <= $Scan->settings->scanMaxThreads && $i <= sizeof($subnets); $i++) {
                //only if index exists!
                if(isset($subnets[$z])) {
                                //start new thread
                    $threads[$z] = new Thread( 'fping_subnet' );
                    $threads[$z]->start_fping( $subnets[$z]['cidr'] );
                    $z++;                               //next index
                        }

As opposed to ping:

for ($i = 0; $i <= $Scan->settings->scanMaxThreads && $i <= sizeof($addresses); $i++) {
                //only if index exists!
                if(isset($addresses[$z])) {
                                //start new thread
                    $threads[$z] = new Thread( 'ping_address' );
                    $threads[$z]->start($Subnets->transform_to_dotted($addresses[$z]['ip_addr']));
                    $z++;                               //next index
                        }

Working as intended for that portion I assume, but it doesn't help the stalling issue on my 172.17.0.0/16 subnet issue.

[routenull0]

Looks like this might be just the way fping works. I timed running fping on the same subnet:

{ time fping -c 1 -g 172.17.0.0/16 ; } 2> /tmp/fping_time.txt
real    27m32.950s
user    0m0.499s
sys     0m8.714s

[routenull0]

Possibly somewhat related to pull request #642.

Testing with the proposed changed, will post results.