In an embodiment a translation of RID (requester identifier) ranges to identifiers of north chips is stored into a south chip. A command that comprises a command RID is received at the south chip from a device. In response, a RID range is determined that encompasses the command RID, and a north chip identifier is found that is assigned a virtual function identified by the command RID. The command is sent from the south chip to the north chip identified by the north chip identifier. The translation comprises a RID compare value and a RID mask. A determination is made that the RID range encompasses the command RID by performing a logical-and operation on the command RID and the RID mask and comparing a result of the logical-and operation to the RID compare value.