1. A method executed at a spine switch in a TRansparent Interconnect of Lots of Links (TRILL) network environment, comprising: storing a portion of virtual PortChannel (vPC) information received from edge switches in Interested vPC Type Length Value (TLV) information of Intermediate System to Intermediate System (IS-IS) routing protocol data units (PDUs), wherein the portion of the vPC information received from the edge switches comprises a hash algorithm associated with the edge switches, and disjoint subsets of hash values for which the edge switches are responsible; deriving, from the portion of vPC information, a physical nickname of a specific one of the edge switches to which a frame can be forwarded, wherein the deriving comprises computing a hash value for the frame based on the hash algorithm specified by the vPC information, and selecting the specific edge switch based on the computed hash value; and rewriting an egress nickname in a TRILL header of the frame with the physical nickname.