How to forward IP packets destined for a Layer 3 broadcast address

This article provides configuration information to forward IP packets destined for a Layer 3 broadcast address.

In the following example, when an IP packet addressed as 10.10.10.255 is sent from the corporate network 192.168.1.0/24, the packets are dropped at the firewall located at the remote office. The intent is to send broadcast addresses addressed to a remote network from corporate network to detect hosts/machines located in a remote office.

How to forward IP packets destined for a Layer 3 broadcast address

Targeted Broadcast Diagram

By default, the router/firewall does not forward the IP packets destined for a Layer 3 broadcast address, as it is designed to break broadcast domain.

To forward IP packets destined for Layer 3 broadcast address, it is necessary to configure the targeted broadcast to an egress interface and/or routing engine.

Perform the following configuration to enable targeted broadcast:

  1. Configure the physical interface:
  2. Configure the logical unit number:
  3. Configure the protocol family inet:
  4. Configure targeted broadcast:
  5. Specify one of the following options:
  • To send packets to the egress interface and to the Routing Engine:
  • To send packets to only the egress interface:

This is not a supported feature in high-end SRX series of devices.

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