Hello Gowthamraj
Like I mentioned before, the reasons for bad sequence numbers are typically the same as the reasons for any bit errors in transmissions such as a bad network connection, or an error in the OS both of which can create corrupted packets. It really depends on what you see as an error. If the sequence numbers you see are not in the right order, or missing, that may be due to delays in the transmission, or dropped packets.
(Remember that the sequence numbers you see in the output don’t necessarily correspond directly to those found within the packet. It depends on how the OS is designed to operate the ping command.)
Within the wireshark output, you see both the identifier and the sequence number, which are calculated in the way I mentioned before. The BE,LE display however is not actually part of the header, but part of the way in which wireshark displays the information found within the header.
According to this wireshark form response, BE stands for big endian, and LE stands for little endian. These terms refer to the “endianness” of the contents found within the field. Endianness refers to the order of the bits within the field. A big-endian ordering places the most significant byte first and the least significant byte last, while a little-endian ordering does the opposite.
By displaying both formats, wireshark makes it easier to follow the sequence numbers that are incrementing from one echo request to the next. It simply shows both formats for the benefit of the user.
You can find out more about endianness at the following link:
I hope this has been helpful!
Laz