Techniques disclosed herein include systems and methods for improving efficiency of multicast state generation within Shortest Path Bridging (SPB) networks. Techniques include using an IS-IS TLV structure with new multicast state computation rules for SPB Networks. SPB Networks use a TLV field for the I-SID Address (and equivalent TLV fields defined in different IETF/IEEE drafts) and node nicknames to signal information that is used to compute a multicast state required to provide L2 Services over a given SPB Network. The I-SID Address TLV is set or filled to carry various items of information. These items of information can include Backbone Media Access Control (B-MAC), Virtual Local Area Network Identifier (VID), I-SID[Transmit, Receive Bit], etc.