[lwip-users] OT: Windows blocking receive broadcasts

[Bill Auerbach]

I just ran into something.  A customer programmed a “bad” static IP address in his lwIP-based device.  My ipconfig utility broadcasts a “who’s there” UDP message and is broadcasted back from the lwIP device the “here I am” packet.  The problem is, with the bad IP address as the source, Windows will not send the packet to the program.  But, Wireshark does show both broadcasts.  Tthe user is not sure what was entered, I can make it happen if I set the lwIP device to 250.168.1.1.  I know it’s in the unicast range, but why is this effecting broadcasts?  Going forward we will better error check the static address that the user enters, but is this broadcast filtering expected?

Thanks,

Bill