A computer program product for use with a computer system having a host and a plurality of clients coupled to one another via a local area network (LAN), to provide a multicasting of messages using a special command set. First computer readable code means is generated for issuing a first special command to add a new IP multicast address providing a group multicast address and an IP multicast address. Then computer readable code means is created for entering said special control command in a multicast routing table, one entry per connection request received. Computer readable code means is then provided for a use count mechanism for keeping track of numbers of communication stacks which have registered with a certain IP multicast address. Also computer readable code means is generated for comparing all inbound IP packets destined for an IP multicast address with said entries in said table and routing all matches to their appropriate communication stacks.