we've developed a NDIS IM driver essentially to filter IP from incoming and
outgoing packets, but

monitoring the destination address in the IP header with some DBGPRINT
instructions in the code, and DbgView outside, we've notice that in some cases
the destination address of outgoing packets is the broadcast address of the
subnet, that is to say, XXX.XXX.XXX.255.

strangely, when we capture the same packet with a sniffer running in other PC,
it has the correct IP in the destination field, and the communication is normal.

the thing is that, when the packets arrive to the IM driver it has a non
filtered address and, of course, the driver just lets it pass.

the app that we use to send text messages between PCs, and for testing the
filtering capabilities of the driver, is working fine in other PCs, so we are
pretty sure is good.

this app is TCP based.

if someone has a clue about this we'll appreciate very much an advice on why is
this happening or how can we solve it.

saludos,

jjtriff