This article provides information about the support extended by MPC's for directed broadcast.
A customer was trying to configure and setup Wake-on-Lan on their MX960 platform. They were able to successfully do so on the EX platform; but are having difficulties on the MX platform. They have enabled the option for broadcasting; but this did not have any effect.
They are using an IRB, rather than a physical/logical interface. To enable this, the customer has to enable targeted-broadcast on the interface <name> unit <number> family inet, in which the unit is the one that contains the IP address of the router for machines on the network. However, the wake-on-lan feature was not functioning in ICHIP based platforms. This feature uses Directed Broadcast on IRB.
Directed broadcast on IRB is supported only on TRIO based platforms in the enhanced-ip mode. Juniper does not plan on supporting this feature on the ICHIP based platforms.