By default, a router will not forward any broadcasts. The problem is most likely that User Datagram Protocol (UDP) ports are not being permitted through the router.
In order to forward UDP broadcasts, the ip helper-address command must be issued on the router interface that will be receiving the broadcasts, as shown in the following example:
router(config)#interface ethernet 0/0
router(config-if)#ip helper-address 10.1.23.5
When the ip helper-address command is configured, by default the following UDP broadcasts are forwarded:
Which one takes precedence when both are configured.