IP Directed Broadcast

IP directed broadcast

An IP directed broadcast is a type of IP packet that

  • has a destination address that is a valid broadcast address for a specific IP subnet but originates from a node outside that subnet, and

  • is forwarded by devices not directly connected to the destination subnet in the same way as unicast IP packets.

The WAN edge device rewrites the destination address in the IP header of the packet to the configured IP broadcast address for the subnet, and then sends the packet as a link-layer broadcast.


Note

The access control list (ACL) option for directed broadcast is not supported in Cisco SD-WAN Manager.

Configure IP directed broadcast using CLI commands

Procedure

Enable the translation of a directed broadcast to physical broadcasts using the ip directed-broadcast command.

Note

 

If you enable directed broadcast on a network interface, any incoming packet that is a broadcast for that subnet is sent out to all devices on that subnet.

By default, ip directed-broadcast is disabled and all IP directed broadcasts are dropped.

Example:

device# configure-transaction
device(config)# interface ethernet 2/1
device(config-if)# ip address 10.114.114.1 255.255.255.0
device(config-if)# ip directed-broadcast
device(config-if)# end