PING weird behaviour

[spandey]

Hi,
I have Ubuntu LUCID. When I try PING -s option, it truncates anything other than 48.Which is strange? What can be the reason?

Here is my IFCONFIG output

spandey@spandey-desktop:~$ ifconfig
eth0 Link encap:Ethernet HWaddr 00:22:b0:e5:91:77
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:29773 errors:0 dropped:0 overruns:0 frame:0
TX packets:24566 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:28659856 (28.6 MB) TX bytes:4767652 (4.7 MB)
Interrupt:21 Base address:0x4000

lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
UP LOOPBACK RUNNING MTU:16436 Metric:1
RX packets:6 errors:0 dropped:0 overruns:0 frame:0
TX packets:6 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:300 (300.0 B) TX bytes:300 (300.0 B)

ppp0 Link encap:Point-to-Point Protocol
inet addr:117.197.247.52 P-t-P:117.197.240.1 Mask:255.255.255.255
UP POINTOPOINT RUNNING NOARP MULTICAST MTU:1492 Metric:1
RX packets:29386 errors:0 dropped:0 overruns:0 frame:0
TX packets:24198 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:3
RX bytes:27976473 (27.9 MB) TX bytes:4224207 (4.2 MB)

spandey@spandey-desktop:~$