How To Test Ip Directed-Broadcast

[Adam Hinchliff]

My initial question is how would you test ip directed-broadcast and no  ip directed-broadcast?

We have a requirement (RSLinx) to enable ip directed-broadcast on some interfaces.

From a networking point of view how would I conduct a before and after test to prove ip directed-broadcast has actually done something? 

Happy to provide more information, just wanted to kick the ball and see who comes back to me. 

Thank you

Adam

[Georg Pauwen]

Hello Adam,

you could send a ping to the broadcast address. Without ip directed broadcast enabled on the interface where the subnet is connected to, you will get no reply. With ip directed broadcast enabled, you will get a response from all hosts on that particular network.

So e.g. send a ping to 192.168.1.255, with ip directed broadcast enabled and disabled on the interface that is the gateway for that subnet.

[Adam Hinchliff]

Hi Georg, 

Thank you for the response.

Yes, I have tried doing that but I was getting 100% success for both disabled and enabled. I need to debug ip-packet to actually see what is happening with the broadcast.

I wiIl report the debugs tomorrow. 

Cheers

Adam

[Georg Pauwen]

Hello Adam,

the test procedure described above doesn't work when you source the ping from a router directly connected to the target network.

Have a look at the document below, it is a pretty comprehensive overview of how to set up the test I described:

IP Directed-Broadcast on Cisco IOS

https://networklessons.com/uncategorized/ip-directed-broadcast-cisco-ios/