StupidScript - 6:23 pm on Jan 25, 2006 (gmt 0)

There are a few reasons why a packet might be invalid. Likely either the packet is badly formed by some element in the transmission process, or (most likely) it is not synching up with an existing request.

It's pretty common for an attack to take the form of a 'packet injection' whereby the attacker tries to gain control of a system by guessing the packet stream's numbering sequence, and then to take control of the packet stream by injecting a forged packet with an address within the guessed range. A successful injection could cause a valid request to become corrupted and possibly result in the compromise of the machine. (Obviously more details are available in lots of different places on the 'net ...)

Sounds like it would be a good idea for you to keep dropping those packets. Your real users probably won't be sending invalid packets at a rate that would cause their valid requests to fail.

BTW, your sample IP came from Indonesia ... according to APNIC [apnic.net], which is fairly popular territory from which this type of abuse flows ...