I am sending a UDP broadcast message from a pc to a VxWorks box with 3 cards, each connected to the network. One of the cards is behind an ethernet switch. The two cards without the switch receive the broadcast message but the card with the switch does not. Can send a unicast message directly the card's IP address and receive it. Have set the subnet mask the same on the offending card as the cards that do receive the broacast message. Is there any obvious reason why this would happen? Any idea on what to look for?