Question: I am running a client application on my Windows 7 machine, it sends a UDP message to another server machine on the local subnet, then server reply with a broadcast UDP message with destination of '192.168.1.255'. The strange thing is that my client application on Windows cannot get the message. I have tried to let the server send a unicast message directly to the ip of my windows machine '192.168.1.8', then the client can get it. I tracked the message using WireShark, and I can see the IP packet sent to '192.168.1.255' but my application cannot get it.

So I believe Windows 7 block the broadcast message in the sub network. I turned off the windows firewall, but it still does not work.

I am almost sure that it's windows's problem, I run the exact same code on another Linux machine in the same subnet, it works good.

Can anyone help me how to solve this problem? Thanks a lot.

Answer: 
Problem solved. Restart windows, add rules to firewall settings, and it's good now.
Add to firewall

```
ANY ANY 255.255.255.255/32 DROP
ANY ANY a.b.c.255/32 DROP 

```

From: <https://www.astaro.org/gateway-products/network-protection-firewall-nat-qos-ips/2568-how-block-broadcast-net-broadcast-packet-udp.html>