1. A computer-executable method for updating routing information associated with a multicast group in an information-centric network (ICN), the method comprising: receiving, by a first node in the ICN, an update message from a neighbor node that specifies a prefix associated with the multicast group and specifies a particular node as a root anchor node of the multicast group, wherein the multicast group includes a plurality of anchor nodes and the root anchor node has a name with a lexicographical value that is smaller than lexicographical values of names of other anchor nodes of the plurality of anchor nodes; determining one or more next-hop neighbors of the first node that: (a) are reporting nodes different from the particular node as the root anchor node; and (b) provide a shortest path to one of the other anchor nodes; and forwarding the update message to the one or more next-hop neighbors.