Red Hat Bugzilla – Bug 115333
ping flood is hardly a flood
Last modified: 2015-03-04 20:13:28 EST
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Description of problem:
ping flood only sends about 70 packets/second (+/- 20), even though
the man page says it should do at least 100 packets/second. This
occurs even when pinging the loopback address, where response whould
be almost instantaneous. If I run tcpdump and watch the packets, the
icmp packets replies occur quickly and then ping waits to send another
request. This is also evident from the ping output which has very low
[root@turbo andrew]# time ping -f localhost
PING localhost.localdomain (127.0.0.1) 56(84) bytes of data.
--- localhost.localdomain ping statistics ---
1530 packets transmitted, 1530 received, 0% packet loss, time 19420ms
rtt min/avg/max/mdev = 0.036/0.044/0.055/0.005 ms, pipe 2, ipg/ewma
Version-Release number of selected component (if applicable):
Steps to Reproduce:
time ping -f localhost
Actual Results: packets per second is less than 100
Expected Results: packets per second should be at least 100
(according to man page)
based on the response for pinging localhost, it should have done
The man page says flood ping does up to 100 packages per second, not
more than 100:
-f Flood ping. For every ECHO_REQUEST sent a period ââ.ââ is
printed, while for ever ECHO_REPLY received a
printed. This provides a rapid display of how many
being dropped. If interval is not given, it sets
zero and outputs packets as fast as they come back or
dred times per second, whichever is more. Only the
may use this option with zero interval.
This new behaviour is wanted as flood ping was know to be used to
"shutdown" remote systems by sending as much packages as possible.
This is now not possible anymore so easily with ping.
Read ya, Phil
> The man page says flood ping does up to 100 packages per second, not
> more than 100:
this is certainly false. The man page says:
> outputs packets as fast as they come back or one hundred times per
> second, whichever is more.
"as fast as they come back" is more than "one hundred times per
second" and should be used, according to the man page.
Ups, true, but then the manpage needs to be corrected at some point as
the code clearly limits to a maximum of 100 packages per second.
Read ya, Phil