IP Directed-Broadcast Command on CISCO Router/Switch

Command

IP Directed-Broadcast

Use

Enables fowarding of directed broadcasts. When this is turned on for an interface, the interface will respond to broadcast messages that are sent to its subnet.

Syntax

Router(config-if)#ip directed-broadcast

Example

IP Directed-Broadcast Command on CISCO Router/Switch 1

In this example, IP directed-broadcasts is enabled on in fa0/0 on R2. A broadcast is sent and the response from both interfaces is received. Next, we issue an IP directed-broadcast to the subnet of fa0/0. Since ip directed-broadcast is enabled on this inteface, it responds.

R2#conf t
Enter configuration commands, one per line. End with CNTL/Z.
R2(config)#int fa0/0
R2(config-if)#ip directed-broadcast

R2(config-if)#do ping 255.255.255.255 repeat 1Type escape sequence to abort.
Sending 1, 100-byte ICMP Echos to 255.255.255.255, timeout is 2 seconds:
Reply to request 0 from 10.1.1.1, 28 ms
Reply to request 0 from 10.2.2.3, 28 ms

R2(config-if)#do ping 10.1.1.255 repeat 1Type escape sequence to abort.
Sending 1, 100-byte ICMP Echos to 10.1.1.255, timeout is 2 seconds:
Reply to request 0 from 10.1.1.1, 24 ms