mandrake 10.0


[root@localhost student]# ping 10.255.240.104
PING 10.255.240.104 (10.255.240.104) 56(84) bytes of data.
64 bytes from 10.255.240.104: icmp_seq=1 ttl=64 time=0.283 ms
64 bytes from 10.255.240.104: icmp_seq=2 ttl=64 time=0.272 ms
64 bytes from 10.255.240.104: icmp_seq=3 ttl=64 time=0.271 ms
64 bytes from 10.255.240.104: icmp_seq=4 ttl=64 time=0.272 ms
64 bytes from 10.255.240.104: icmp_seq=5 ttl=64 time=0.284 ms

--- 10.255.240.104 ping statistics ---
5 packets transmitted, 5 received, 0% packet loss, time 3996ms
rtt min/avg/max/mdev = 0.271/0.276/0.284/0.015 ms
[root@localhost student]# ping -f -s 10240 10.255.240.104
PING 10.255.240.104 (10.255.240.104) 10240(10268) bytes of data.
.................................................................................................... ........................................................................................
--- 10.255.240.104 ping statistics ---
545 packets transmitted, 360 received, 33% packet loss, time 7770ms
rtt min/avg/max/mdev = 17.541/85.374/288.097/51.940 ms, pipe 20, ipg/ewma 14.284/100.001 ms


why this loss?

It isn't a loss. Running ping with -f causes flood ping. All those dots mean something. From the ping man page:

-f Flood ping. For every ECHO_REQUEST sent a period ``.'' is
printed, while for ever ECHO_REPLY received a backspace is
printed. This provides a rapid display of how many packets are
being dropped. If interval is not given, it sets interval to
zero and outputs packets as fast as they come back or one hun-
dred times per second, whichever is more. Only the super-user
may use this option with zero interval.