Re: [lwip-users] OT: Windows blocking receive broadcasts

[Kieran Mansley]

On 21 Dec 2010, at 19:24, Bill Auerbach wrote:

> 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?

I would guess that Windows is comparing the broadcast address being used to its 
own interface configuration and deciding that this is a broadcast on a 
different IP network, so it drops it.

Kieran