fping tuning

[Schwimmer, Eric E *HS]

We're monitoring 1420 IPs in hobbit, and it takes fping
~40 seconds to go through them all:

<snip>
[root at hobbit fping]# fping -i5 -b12 -f ips -r1 -t250 -B2 -q -s
    1430 targets
    1419 alive
      11 unreachable
       0 unknown addresses

      55 timeouts (waiting for response)
    1474 ICMP Echos sent
    1420 ICMP Echo Replies received
       0 other ICMP received

 0.05 ms (min round trip time)
 5.83 ms (avg round trip time)
 281 ms (max round trip time)
       40.704 sec (elapsed real time)
</snip>

Now, this seems a bit lengthy to me.  I mean, if the avg
round trip time is 5.83 ms, and there are 1430 hosts, 
should the total time in transit for all hosts should
be 8336ms, or 8 seconds... right?  Even when I remove the
hosts that aren't responding, the results on are par with
those above.

Our polling interval is once every 60 seconds (which we want 
to maintain, because we like to know ASAP when something drops
even one ping), so it's not a problem yet. We add hosts on a 
daily basis, however, so it will be a problem some time in 
the future and I'd like to fix it before it becomes a problem.

This machine is a dual 3GHz Xeon /w 6GB of memory,
running Fedora Core 5.  I've flipped every bit in the kernel
parameters that I dare via sysctl, with little to no effect
on the poll time.  Does anybody out there have any
recommendations on a way to speed this up?

Regards,
-Eric Schwimmer
Network Engineer
UVA HSCS Network Engineering